Don't show replies from other threads in the tree mode

boards/models/post/__init__.py

@@ -193,7 +193,9 b' class Post(models.Model, Viewable):'
         return 'P#{}/{}'.format(self.id, self.title)
 
     def get_referenced_posts(self):
-        return self.referenced_posts.order_by('pub_time')
+        threads = self.get_threads().all()
+        return self.referenced_posts.filter(threads__in=threads)\
+                .order_by('pub_time').distinct().all()
 
     def get_title(self) -> str:
         """