diff --git a/src/applications/phriction/query/PhrictionDocumentQuery.php b/src/applications/phriction/query/PhrictionDocumentQuery.php
--- a/src/applications/phriction/query/PhrictionDocumentQuery.php
+++ b/src/applications/phriction/query/PhrictionDocumentQuery.php
@@ -10,6 +10,9 @@
   private $slugPrefix;
   private $statuses;
 
+  private $parentPaths;
+  private $ancestorPaths;
+
   private $needContent;
 
   const ORDER_HIERARCHY = 'hierarchy';
@@ -34,7 +37,7 @@
     return $this;
   }
 
-  public function  withSlugPrefix($slug_prefix) {
+  public function withSlugPrefix($slug_prefix) {
     $this->slugPrefix = $slug_prefix;
     return $this;
   }
@@ -44,6 +47,16 @@
     return $this;
   }
 
+  public function withParentPaths(array $paths) {
+    $this->parentPaths = $paths;
+    return $this;
+  }
+
+  public function withAncestorPaths(array $paths) {
+    $this->ancestorPaths = $paths;
+    return $this;
+  }
+
   public function needContent($need_content) {
     $this->needContent = $need_content;
     return $this;
@@ -214,6 +227,94 @@
         $this->depths);
     }
 
+    if ($this->parentPaths !== null || $this->ancestorPaths !== null) {
+      $sets = array(
+        array(
+          'paths' => $this->parentPaths,
+          'parents' => true,
+        ),
+        array(
+          'paths' => $this->ancestorPaths,
+          'parents' => false,
+        ),
+      );
+
+      $paths = array();
+      foreach ($sets as $set) {
+        $set_paths = $set['paths'];
+        if ($set_paths === null) {
+          continue;
+        }
+
+        if (!$set_paths) {
+          throw new PhabricatorEmptyQueryException(
+            pht('No parent/ancestor paths specified.'));
+        }
+
+        $is_parents = $set['parents'];
+        foreach ($set_paths as $path) {
+          $path_normal = PhabricatorSlug::normalize($path);
+          if ($path !== $path_normal) {
+            throw new Exception(
+              pht(
+                'Document path "%s" is not a valid path. The normalized '.
+                'form of this path is "%s".',
+                $path,
+                $path_normal));
+          }
+
+          $depth = PhabricatorSlug::getDepth($path_normal);
+          if ($is_parents) {
+            $min_depth = $depth + 1;
+            $max_depth = $depth + 1;
+          } else {
+            $min_depth = $depth + 1;
+            $max_depth = null;
+          }
+
+          $paths[] = array(
+            $path_normal,
+            $min_depth,
+            $max_depth,
+          );
+        }
+      }
+
+      $path_clauses = array();
+      foreach ($paths as $path) {
+        $parts = array();
+        list($prefix, $min, $max) = $path;
+
+        // If we're getting children or ancestors of the root document, they
+        // aren't actually stored with the leading "/" in the database, so
+        // just skip this part of the clause.
+        if ($prefix !== '/') {
+          $parts[] = qsprintf(
+            $conn,
+            'd.slug LIKE %>',
+            $prefix);
+        }
+
+        if ($min !== null) {
+          $parts[] = qsprintf(
+            $conn,
+            'd.depth >= %d',
+            $min);
+        }
+
+        if ($max !== null) {
+          $parts[] = qsprintf(
+            $conn,
+            'd.depth <= %d',
+            $max);
+        }
+
+        $path_clauses[] = '('.implode(') AND (', $parts).')';
+      }
+
+      $where[] = '('.implode(') OR (', $path_clauses).')';
+    }
+
     return $where;
   }
 
diff --git a/src/applications/phriction/query/PhrictionDocumentSearchEngine.php b/src/applications/phriction/query/PhrictionDocumentSearchEngine.php
--- a/src/applications/phriction/query/PhrictionDocumentSearchEngine.php
+++ b/src/applications/phriction/query/PhrictionDocumentSearchEngine.php
@@ -27,6 +27,14 @@
       $query->withSlugs($map['paths']);
     }
 
+    if ($map['parentPaths']) {
+      $query->withParentPaths($map['parentPaths']);
+    }
+
+    if ($map['ancestorPaths']) {
+      $query->withAncestorPaths($map['ancestorPaths']);
+    }
+
     return $query;
   }
 
@@ -40,6 +48,14 @@
         ->setKey('paths')
         ->setIsHidden(true)
         ->setLabel(pht('Paths')),
+      id(new PhabricatorSearchStringListField())
+        ->setKey('parentPaths')
+        ->setIsHidden(true)
+        ->setLabel(pht('Parent Paths')),
+      id(new PhabricatorSearchStringListField())
+        ->setKey('ancestorPaths')
+        ->setIsHidden(true)
+        ->setLabel(pht('Ancestor Paths')),
     );
   }