diff --git a/src/main/java/com/guo/learningprogresstracker/controller/ReviewController.java b/src/main/java/com/guo/learningprogresstracker/controller/ReviewController.java
index a4cacb0..a88baaf 100644
--- a/src/main/java/com/guo/learningprogresstracker/controller/ReviewController.java
+++ b/src/main/java/com/guo/learningprogresstracker/controller/ReviewController.java
@@ -24,7 +24,7 @@ import org.springframework.web.multipart.MultipartFile;
 
 import java.io.IOException;
 import java.util.List;
-import java.util.List;
+import java.util.Map;
 
 /**
  * 复习模块控制层 — 复习内容滚动展示与交互
@@ -159,7 +159,18 @@ public class ReviewController {
     public CommonResult<ReviewStandardMindMapEntity> recallCompare(
             @PathVariable String taskNum,
             @Valid @RequestBody RecallCompareRequest request) throws NotFindEntitiesException, OperationFailedException {
-        return CommonResult.success(standardMindMapService.recallCompare(taskNum, request.getRecallOutline(), request.getSessionNum()));
+        return CommonResult.success(standardMindMapService.recallCompare(taskNum, request.getRecallOutline(), request.getFocusPath()));
+    }
+
+    /**
+     * 在标准导图中查找与给定内容最匹配的节点
+     */
+    @PostMapping("/standard-mind-map/{taskNum}/find-node")
+    public CommonResult<Map<String, Object>> findNode(
+            @PathVariable String taskNum,
+            @RequestBody Map<String, String> body) throws NotFindEntitiesException, OperationFailedException {
+        String content = body != null ? body.getOrDefault("content", "") : "";
+        return CommonResult.success(standardMindMapService.findNode(taskNum, content));
     }
 
     /**
diff --git a/src/main/java/com/guo/learningprogresstracker/controller/StudySessionController.java b/src/main/java/com/guo/learningprogresstracker/controller/StudySessionController.java
index c913f35..d0b5bda 100644
--- a/src/main/java/com/guo/learningprogresstracker/controller/StudySessionController.java
+++ b/src/main/java/com/guo/learningprogresstracker/controller/StudySessionController.java
@@ -18,9 +18,7 @@ import lombok.RequiredArgsConstructor;
 import org.springframework.validation.annotation.Validated;
 import org.springframework.web.bind.annotation.*;
 
-import com.guo.learningprogresstracker.dto.response.SessionBriefVO;
 import java.util.ArrayList;
-import java.util.List;
 import java.time.LocalDateTime;
 
 /**
@@ -139,10 +137,4 @@ public class StudySessionController {
             @RequestParam(required = false) String excludeTaskNum) {
         return CommonResult.success(studySessionsServiceImpl.getActiveSession(excludeTaskNum));
     }
-
-    /** 获取任务的所有会话简要列表（用于复习维度选择） */
-    @GetMapping("/tasks/{taskNum}/sessions")
-    public CommonResult<List<SessionBriefVO>> getTaskSessions(@PathVariable String taskNum) {
-        return CommonResult.success(studySessionsServiceImpl.getTaskSessions(taskNum));
-    }
 }
diff --git a/src/main/java/com/guo/learningprogresstracker/dto/request/RecallCompareRequest.java b/src/main/java/com/guo/learningprogresstracker/dto/request/RecallCompareRequest.java
index d5f055c..a9e88a8 100644
--- a/src/main/java/com/guo/learningprogresstracker/dto/request/RecallCompareRequest.java
+++ b/src/main/java/com/guo/learningprogresstracker/dto/request/RecallCompareRequest.java
@@ -12,6 +12,6 @@ public class RecallCompareRequest {
     @NotBlank(message = "回忆大纲不可为空")
     private String recallOutline;
 
-    /** 复习维度：会话编码，null 为任务维度 */
-    private String sessionNum;
+    /** 复习起点节点路径（以 / 分隔），null 为任务维度 */
+    private String focusPath;
 }
diff --git a/src/main/java/com/guo/learningprogresstracker/dto/response/SessionBriefVO.java b/src/main/java/com/guo/learningprogresstracker/dto/response/SessionBriefVO.java
deleted file mode 100644
index 75c2576..0000000
--- a/src/main/java/com/guo/learningprogresstracker/dto/response/SessionBriefVO.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package com.guo.learningprogresstracker.dto.response;
-
-import lombok.Data;
-
-/**
- * 会话简要信息（用于复习维度选择列表）
- */
-@Data
-public class SessionBriefVO {
-    private String sessionNum;
-    private String startTime;
-    private String expectation;
-    private int reportCount;
-    private int fragmentCount;
-}
diff --git a/src/main/java/com/guo/learningprogresstracker/entity/ReviewRecallRecordEntity.java b/src/main/java/com/guo/learningprogresstracker/entity/ReviewRecallRecordEntity.java
index a0f704a..82aa56b 100644
--- a/src/main/java/com/guo/learningprogresstracker/entity/ReviewRecallRecordEntity.java
+++ b/src/main/java/com/guo/learningprogresstracker/entity/ReviewRecallRecordEntity.java
@@ -25,10 +25,10 @@ public class ReviewRecallRecordEntity extends BaseEntity implements Serializable
     private Integer standardMapId;
 
     /**
-     * 复习维度：会话编码（null 表示任务维度复习）
+     * 复习起点节点路径（以 / 分隔），null 表示任务维度复习
      */
-    @TableField(value = "session_num")
-    private String sessionNum;
+    @TableField(value = "focus_path")
+    private String focusPath;
 
     /**
      * 用户回忆绘制的导图大纲文本
diff --git a/src/main/java/com/guo/learningprogresstracker/service/StandardMindMapService.java b/src/main/java/com/guo/learningprogresstracker/service/StandardMindMapService.java
index 734cf71..779a140 100644
--- a/src/main/java/com/guo/learningprogresstracker/service/StandardMindMapService.java
+++ b/src/main/java/com/guo/learningprogresstracker/service/StandardMindMapService.java
@@ -6,6 +6,7 @@ import com.guo.learningprogresstracker.exception.NotFindEntitiesException;
 import com.guo.learningprogresstracker.exception.OperationFailedException;
 
 import java.util.List;
+import java.util.Map;
 
 /**
  * 标准思维导图服务。
@@ -37,10 +38,16 @@ public interface StandardMindMapService {
      * 用户提交回忆大纲，与标准导图对比并返回结果。
      *
      * @param recallOutline 用户回忆的缩进大纲文本
-     * @param sessionNum    可选会话编码，指定时仅对比该会话相关的标准导图节点
-     * @return 对比记录实体（compareResult 字段包含对比树 JSON）
+     * @param focusPath     可选：标准导图中的节点路径（/ 分隔），指定后仅对比该子树
      */
-    ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline, String sessionNum) throws NotFindEntitiesException, OperationFailedException;
+    ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline, String focusPath) throws NotFindEntitiesException, OperationFailedException;
+
+    /**
+     * 根据内容文本在标准导图中查找最匹配的节点，返回节点路径。
+     *
+     * @return { "path": "节点A / 节点B", "nodeTitle": "节点B", "score": 0.85 }
+     */
+    Map<String, Object> findNode(String taskNum, String content) throws NotFindEntitiesException, OperationFailedException;
 
     /**
      * 获取该任务的所有回忆对比记录。
diff --git a/src/main/java/com/guo/learningprogresstracker/service/StudySessionsService.java b/src/main/java/com/guo/learningprogresstracker/service/StudySessionsService.java
index 76630fb..9932da1 100644
--- a/src/main/java/com/guo/learningprogresstracker/service/StudySessionsService.java
+++ b/src/main/java/com/guo/learningprogresstracker/service/StudySessionsService.java
@@ -11,9 +11,7 @@ import com.baomidou.mybatisplus.extension.service.IService;
 import com.guo.learningprogresstracker.exception.ErrorParameterException;
 
 import java.time.LocalDateTime;
-import com.guo.learningprogresstracker.dto.response.SessionBriefVO;
 import java.util.ArrayList;
-import java.util.List;
 
 /**
 * @author guo
@@ -37,7 +35,4 @@ public interface StudySessionsService extends IService<StudySessionsEntity> {
     Page<StudyReportsEntity> getTaskReports(String taskNum, int page, int size, String keyword);
 
     StudySessionResponse getActiveSession(String excludeTaskNum);
-
-    /** 获取任务的所有会话简要信息（复习维度选择用） */
-    List<SessionBriefVO> getTaskSessions(String taskNum);
 }
diff --git a/src/main/java/com/guo/learningprogresstracker/service/impl/BuiltinMindMapGenerator.java b/src/main/java/com/guo/learningprogresstracker/service/impl/BuiltinMindMapGenerator.java
index 2c208af..e6be4a9 100644
--- a/src/main/java/com/guo/learningprogresstracker/service/impl/BuiltinMindMapGenerator.java
+++ b/src/main/java/com/guo/learningprogresstracker/service/impl/BuiltinMindMapGenerator.java
@@ -84,7 +84,6 @@ public class BuiltinMindMapGenerator implements MindMapAiClient {
             }
 
             MindMapNode sessionNode = new MindMapNode(sessionTitle);
-            sessionNode.setSessionNum(sessionNum);
 
             // 报告作为子节点
             for (StudyReportsEntity report : sessReports) {
@@ -94,7 +93,6 @@ public class BuiltinMindMapGenerator implements MindMapAiClient {
                 reportNode.setNotes(content);
                 reportNode.setSourceType("REPORT");
                 reportNode.setSourceId(report.getId());
-                reportNode.setSessionNum(sessionNum);
                 sessionNode.getChildren().add(reportNode);
             }
 
@@ -106,7 +104,6 @@ public class BuiltinMindMapGenerator implements MindMapAiClient {
                 fragNode.setNotes(content);
                 fragNode.setSourceType("FRAGMENT");
                 fragNode.setSourceId(frag.getId());
-                fragNode.setSessionNum(sessionNum);
                 sessionNode.getChildren().add(fragNode);
             }
 
diff --git a/src/main/java/com/guo/learningprogresstracker/service/impl/StandardMindMapServiceImpl.java b/src/main/java/com/guo/learningprogresstracker/service/impl/StandardMindMapServiceImpl.java
index e1c0c58..ae9fdc9 100644
--- a/src/main/java/com/guo/learningprogresstracker/service/impl/StandardMindMapServiceImpl.java
+++ b/src/main/java/com/guo/learningprogresstracker/service/impl/StandardMindMapServiceImpl.java
@@ -152,7 +152,7 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
 
     @Override
     @Transactional
-    public ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline, String sessionNum)
+    public ReviewStandardMindMapEntity recallCompare(String taskNum, String recallOutline, String focusPath)
             throws NotFindEntitiesException, OperationFailedException {
         ensureTaskExists(taskNum);
 
@@ -163,9 +163,14 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
         MindMapNode standardRoot = MindMapTreeTool.fromJson(standard.getContent(), objectMapper);
         MindMapNode recallRoot = MindMapTreeTool.parseOutline(recallOutline);
 
-        // 2b. 若指定了会话维度，过滤标准导图只保留该会话相关节点
-        if (sessionNum != null && !sessionNum.isBlank()) {
-            standardRoot = MindMapTreeTool.filterBySession(standardRoot, sessionNum);
+        // 2b. 若指定了起点节点路径，提取该子树作为对比基准
+        MindMapNode compareRoot = standardRoot;
+        if (focusPath != null && !focusPath.isBlank()) {
+            compareRoot = MindMapTreeTool.extractSubtree(standardRoot, focusPath);
+            if (compareRoot == null) {
+                log.warn("focusPath 未匹配到节点，使用全量标准导图: path={}", focusPath);
+                compareRoot = standardRoot;
+            }
         }
 
         // 3. 执行对比（优先 AI 语义对比，失败时降级为内置算法）
@@ -176,19 +181,19 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
                     .getTaskName();
             var optJson = aiServiceClient.compareRecall(
                     taskName,
-                    MindMapTreeTool.toFullOutline(standardRoot),
+                    MindMapTreeTool.toFullOutline(compareRoot),
                     recallOutline
             );
             if (optJson.isPresent()) {
-                result = buildCompareResultFromAI(optJson.get(), standardRoot);
+                result = buildCompareResultFromAI(optJson.get(), compareRoot);
                 log.info("AI 回忆对比: taskNum={}, recallRatio={}, evaluation={}",
                         taskNum, result.getRecallRatio(),
                         result.getEvaluation() != null ? result.getEvaluation().substring(0, Math.min(50, result.getEvaluation().length())) : "");
             } else {
-                result = compareTrees(standardRoot, recallRoot);
+                result = compareTrees(compareRoot, recallRoot);
             }
         } else {
-            result = compareTrees(standardRoot, recallRoot);
+            result = compareTrees(compareRoot, recallRoot);
         }
 
         // 4. 序列化对比结果
@@ -203,7 +208,7 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
         ReviewRecallRecordEntity record = new ReviewRecallRecordEntity();
         record.setTaskNum(taskNum);
         record.setStandardMapId(standard.getId());
-        record.setSessionNum(sessionNum != null && !sessionNum.isBlank() ? sessionNum : null);
+        record.setFocusPath(focusPath != null && !focusPath.isBlank() ? focusPath : null);
         record.setRecallContent(recallOutline);
         record.setCompareResult(resultJson);
         record.setRecallRatio(result.getRecallRatio());
@@ -219,6 +224,29 @@ public class StandardMindMapServiceImpl implements StandardMindMapService {
         return standard;
     }
 
+    // ============ 节点查找 ============
+
+    @Override
+    public Map<String, Object> findNode(String taskNum, String content) throws NotFindEntitiesException, OperationFailedException {
+        ensureTaskExists(taskNum);
+        ReviewStandardMindMapEntity standard = getOrGenerate(taskNum);
+        MindMapNode root = MindMapTreeTool.fromJson(standard.getContent(), objectMapper);
+
+        MindMapNode closest = MindMapTreeTool.findClosestNode(root, content);
+        Map<String, Object> result = new LinkedHashMap<>();
+        if (closest != null) {
+            String path = MindMapTreeTool.getPath(root, closest.getTitle());
+            result.put("path", path);
+            result.put("nodeTitle", closest.getTitle());
+            result.put("score", MindMapTreeTool.similarityScore(closest.getTitle(), content));
+        } else {
+            result.put("path", "");
+            result.put("nodeTitle", "");
+            result.put("score", 0.0);
+        }
+        return result;
+    }
+
     // ============ 对比算法核心 ============
 
     /**
diff --git a/src/main/java/com/guo/learningprogresstracker/service/impl/StudySessionsServiceImpl.java b/src/main/java/com/guo/learningprogresstracker/service/impl/StudySessionsServiceImpl.java
index b7495fc..fcc93d6 100644
--- a/src/main/java/com/guo/learningprogresstracker/service/impl/StudySessionsServiceImpl.java
+++ b/src/main/java/com/guo/learningprogresstracker/service/impl/StudySessionsServiceImpl.java
@@ -5,7 +5,6 @@ import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import com.google.protobuf.ServiceException;
 import com.guo.learningprogresstracker.dto.StudySessionsDto;
-import com.guo.learningprogresstracker.dto.response.SessionBriefVO;
 import com.guo.learningprogresstracker.dto.response.StudySessionResponse;
 import com.guo.learningprogresstracker.entity.StudyReportFragmentsEntity;
 import com.guo.learningprogresstracker.entity.StudyReportsEntity;
@@ -27,7 +26,6 @@ import org.springframework.transaction.annotation.Transactional;
 
 import java.time.LocalDateTime;
 import java.util.ArrayList;
-import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
@@ -227,34 +225,6 @@ public class StudySessionsServiceImpl extends ServiceImpl<StudySessionsMapper, S
         return result;
     }
 
-    // ============ 获取任务会话列表（复习维度选择用） ============
-
-    @Override
-    public List<SessionBriefVO> getTaskSessions(String taskNum) {
-        var sessions = this.list(Wrappers.lambdaQuery(StudySessionsEntity.class)
-                .eq(StudySessionsEntity::getTaskNum, taskNum)
-                .orderByDesc(StudySessionsEntity::getStartTime));
-
-        return sessions.stream().map(s -> {
-            SessionBriefVO vo = new SessionBriefVO();
-            vo.setSessionNum(s.getSessionNum());
-            vo.setStartTime(s.getStartTime() != null ? s.getStartTime().toString() : null);
-            // 查询该会话的预期
-            Optional.ofNullable(studyExpectationsService.getBySessionNum(s.getSessionNum()))
-                    .ifPresent(e -> vo.setExpectation(e.getDescription()));
-            // 统计报告和残片数量
-            long reportCount = studyReportsMapper.selectCount(
-                    Wrappers.lambdaQuery(StudyReportsEntity.class)
-                            .eq(StudyReportsEntity::getSessionNum, s.getSessionNum()));
-            long fragmentCount = studyReportFragmentsMapper.selectCount(
-                    Wrappers.lambdaQuery(StudyReportFragmentsEntity.class)
-                            .eq(StudyReportFragmentsEntity::getSessionNum, s.getSessionNum()));
-            vo.setReportCount((int) reportCount);
-            vo.setFragmentCount((int) fragmentCount);
-            return vo;
-        }).collect(Collectors.toList());
-    }
-
     // ============ 活跃会话查询 ============
 
     /**
diff --git a/src/main/java/com/guo/learningprogresstracker/utils/MindMapNode.java b/src/main/java/com/guo/learningprogresstracker/utils/MindMapNode.java
index 53d285c..78d126a 100644
--- a/src/main/java/com/guo/learningprogresstracker/utils/MindMapNode.java
+++ b/src/main/java/com/guo/learningprogresstracker/utils/MindMapNode.java
@@ -35,8 +35,6 @@ public class MindMapNode {
     private String notes;
     private String sourceType;
     private Integer sourceId;
-    /** 可选：节点来源会话编码（REPORT/FRAGMENT 节点使用） */
-    private String sessionNum;
     private List<MindMapNode> children;
 
     public MindMapNode(String title) {
@@ -53,7 +51,6 @@ public class MindMapNode {
         map.put("notes", notes != null ? notes : "");
         if (sourceType != null) map.put("sourceType", sourceType);
         if (sourceId != null) map.put("sourceId", sourceId);
-        if (sessionNum != null) map.put("sessionNum", sessionNum);
         List<Object> childMaps = new ArrayList<>();
         if (children != null) {
             for (MindMapNode c : children) {
@@ -73,7 +70,6 @@ public class MindMapNode {
         if (map.containsKey("sourceId") && map.get("sourceId") != null) {
             node.setSourceId(((Number) map.get("sourceId")).intValue());
         }
-        node.setSessionNum((String) map.get("sessionNum"));
         Object raw = map.getOrDefault("children", map.get("nodes"));
         List<MindMapNode> children = new ArrayList<>();
         if (raw instanceof List<?> list) {
diff --git a/src/main/java/com/guo/learningprogresstracker/utils/MindMapTreeTool.java b/src/main/java/com/guo/learningprogresstracker/utils/MindMapTreeTool.java
index cd2e503..1c13405 100644
--- a/src/main/java/com/guo/learningprogresstracker/utils/MindMapTreeTool.java
+++ b/src/main/java/com/guo/learningprogresstracker/utils/MindMapTreeTool.java
@@ -156,50 +156,6 @@ public class MindMapTreeTool {
         return 1 + node.getChildren().stream().mapToInt(MindMapTreeTool::maxDepth).max().orElse(0);
     }
 
-    /**
-     * 过滤树：只保留与指定 sessionNum 相关的分支。
-     * - 节点有 sessionNum 且匹配 → 保留
-     * - 节点无 sessionNum（如 APPLICATION 或 AI 生成的节点） → 保留（视为任务级通用知识）
-     * - 有子节点被保留时，父节点也保留
-     *
-     * @param root       树根
-     * @param sessionNum 目标会话编码
-     * @return 过滤后的树，若无相关节点则返回仅含根的空树
-     */
-    public static MindMapNode filterBySession(MindMapNode root, String sessionNum) {
-        if (root == null || sessionNum == null || sessionNum.isBlank()) return root;
-        MindMapNode filtered = filterRecursive(root, sessionNum);
-        return filtered != null ? filtered : new MindMapNode(root.getTitle() != null ? root.getTitle() : "");
-    }
-
-    private static MindMapNode filterRecursive(MindMapNode node, String sessionNum) {
-        if (node == null) return null;
-
-        // 先过滤子节点
-        List<MindMapNode> keptChildren = new ArrayList<>();
-        if (node.getChildren() != null) {
-            for (MindMapNode child : node.getChildren()) {
-                MindMapNode kept = filterRecursive(child, sessionNum);
-                if (kept != null) {
-                    keptChildren.add(kept);
-                }
-            }
-        }
-
-        // 判断当前节点是否应该保留：
-        // 1. 有 sessionNum 且匹配 → 保留
-        // 2. 无 sessionNum → 保留（任务级节点，如 APPLICATION 或 AI 生成）
-        // 3. 有子节点保留 → 保留
-        boolean selfMatch = (node.getSessionNum() == null) || sessionNum.equals(node.getSessionNum());
-        if (selfMatch || !keptChildren.isEmpty()) {
-            MindMapNode result = copyNodeShallow(node);
-            result.setChildren(keptChildren.isEmpty() ? node.getChildren() : keptChildren);
-            return result;
-        }
-
-        return null;
-    }
-
     /** 浅拷贝节点（仅拷贝标量字段，不拷贝 children） */
     private static MindMapNode copyNodeShallow(MindMapNode node) {
         MindMapNode copy = new MindMapNode();
@@ -207,10 +163,138 @@ public class MindMapTreeTool {
         copy.setNotes(node.getNotes());
         copy.setSourceType(node.getSourceType());
         copy.setSourceId(node.getSourceId());
-        copy.setSessionNum(node.getSessionNum());
         return copy;
     }
 
+    /**
+     * 按路径提取子树：以 / 分隔的节点标题路径，提取目标节点为根的新树。
+     * @param root 完整树根
+     * @param path 节点路径，如 "根标题 / 分支A / 子节点B"
+     * @return 以路径末端节点为根的深拷贝子树，匹配失败时返回 null
+     */
+    public static MindMapNode extractSubtree(MindMapNode root, String path) {
+        if (root == null || path == null || path.isBlank()) return null;
+        String[] segments = path.split("\\s*/\\s*");
+        MindMapNode current = root;
+        for (int i = 0; i < segments.length; i++) {
+            String seg = segments[i].trim();
+            if (seg.isEmpty()) continue;
+            if (current.getTitle() != null && normalizeForMerge(current.getTitle()).equals(normalizeForMerge(seg))) {
+                continue; // 当前节点已匹配，看下一段
+            }
+            MindMapNode found = null;
+            if (current.getChildren() != null) {
+                for (MindMapNode child : current.getChildren()) {
+                    if (child.getTitle() != null && normalizeForMerge(child.getTitle()).equals(normalizeForMerge(seg))) {
+                        found = child;
+                        break;
+                    }
+                }
+            }
+            if (found != null) {
+                current = found;
+            } else {
+                return null;
+            }
+        }
+        return deepCopy(current);
+    }
+
+    /** 深拷贝节点及其子树 */
+    private static MindMapNode deepCopy(MindMapNode node) {
+        if (node == null) return null;
+        MindMapNode copy = new MindMapNode();
+        copy.setTitle(node.getTitle());
+        copy.setNotes(node.getNotes());
+        copy.setSourceType(node.getSourceType());
+        copy.setSourceId(node.getSourceId());
+        List<MindMapNode> children = new ArrayList<>();
+        if (node.getChildren() != null) {
+            for (MindMapNode child : node.getChildren()) {
+                children.add(deepCopy(child));
+            }
+        }
+        copy.setChildren(children);
+        return copy;
+    }
+
+    /**
+     * 查找与 content 最相似的节点。基于 title 的 bigram Jaccard 相似度。
+     * @return 得分最高的节点，若所有节点得分均低于 0.1 则返回 null
+     */
+    public static MindMapNode findClosestNode(MindMapNode root, String content) {
+        if (root == null || content == null || content.isBlank()) return null;
+        List<MindMapNode> flat = flatten(root);
+        MindMapNode best = null;
+        double bestScore = 0.0;
+        for (MindMapNode node : flat) {
+            if (node.getTitle() == null || node.getTitle().isBlank()) continue;
+            double score = similarityScore(node.getTitle(), content);
+            // notes 也参与匹配，但权重减半
+            if (node.getNotes() != null && !node.getNotes().isBlank()) {
+                double noteScore = similarityScore(node.getNotes(), content);
+                score = Math.max(score, noteScore * 0.5);
+            }
+            if (score > bestScore) {
+                bestScore = score;
+                best = node;
+            }
+        }
+        return bestScore > 0.1 ? best : null;
+    }
+
+    /**
+     * 获取节点在树中的路径（以 / 分隔的 title 序列）
+     */
+    public static String getPath(MindMapNode root, String targetTitle) {
+        if (root == null || targetTitle == null) return "";
+        List<String> path = new ArrayList<>();
+        if (findPathRecursive(root, targetTitle, path)) {
+            return String.join(" / ", path);
+        }
+        return "";
+    }
+
+    private static boolean findPathRecursive(MindMapNode node, String targetTitle, List<String> path) {
+        if (node == null) return false;
+        path.add(node.getTitle() != null ? node.getTitle() : "");
+        if (normalizeForMerge(node.getTitle()).equals(normalizeForMerge(targetTitle))) return true;
+        if (node.getChildren() != null) {
+            for (MindMapNode child : node.getChildren()) {
+                if (findPathRecursive(child, targetTitle, path)) return true;
+            }
+        }
+        path.remove(path.size() - 1);
+        return false;
+    }
+
+    /** bigram Jaccard 相似度 */
+    public static double similarityScore(String a, String b) {
+        if (a == null || b == null) return 0;
+        String na = normalizeForMerge(a);
+        String nb = normalizeForMerge(b);
+        if (na.isEmpty() || nb.isEmpty()) return 0;
+        if (na.equals(nb)) return 1.0;
+        // 子串匹配
+        if (na.contains(nb) || nb.contains(na)) return 0.9;
+        Set<String> bigramsA = bigrams(na);
+        Set<String> bigramsB = bigrams(nb);
+        if (bigramsA.isEmpty() && bigramsB.isEmpty()) return 0;
+        Set<String> union = new HashSet<>(bigramsA);
+        union.addAll(bigramsB);
+        Set<String> intersect = new HashSet<>(bigramsA);
+        intersect.retainAll(bigramsB);
+        return (double) intersect.size() / union.size();
+    }
+
+    private static Set<String> bigrams(String s) {
+        Set<String> set = new LinkedHashSet<>();
+        for (int i = 0; i < s.length() - 1; i++) {
+            set.add(s.substring(i, i + 2));
+        }
+        return set;
+    }
+
     /**
      * 合并新旧树：保留旧树中已有节点（用户编辑），追加新树中的新节点。
      * 按标准化标题匹配同级节点，旧树匹配到的节点优先保留。
diff --git a/src/main/resources/db/migration/V20260706_1__add_focus_path_to_recall_records.sql b/src/main/resources/db/migration/V20260706_1__add_focus_path_to_recall_records.sql
new file mode 100644
index 0000000..67881aa
--- /dev/null
+++ b/src/main/resources/db/migration/V20260706_1__add_focus_path_to_recall_records.sql
@@ -0,0 +1,3 @@
+-- 为回忆对比记录添加 focus_path 字段，支持节点级复习范围
+ALTER TABLE review_recall_records
+    ADD COLUMN focus_path VARCHAR(512) NULL AFTER session_num;