diff --git a/src/Query/GroupOption.php b/src/Query/GroupOption.php
index f5fb70a..5afb03e 100644
--- a/src/Query/GroupOption.php
+++ b/src/Query/GroupOption.php
@@ -106,15 +106,18 @@ class GroupOption implements QueryOptionInterface, QueryOptionTreeItemInterface
   /**
    * {@inheritdoc}
    */
-  public function apply($query) {
+  public function apply($query, $original_query = NULL) {
+    if (is_null($original_query)) {
+      $original_query = $query;
+    }
     switch ($this->conjunction) {
       case 'OR':
-        $group = $query->orConditionGroup();
+        $group = $original_query->orConditionGroup();
         break;
 
       case 'AND':
       default:
-        $group = $query->andConditionGroup();
+        $group = $original_query->andConditionGroup();
         break;
     }
 
@@ -125,8 +128,8 @@ class GroupOption implements QueryOptionInterface, QueryOptionTreeItemInterface
     }
 
     if (!empty($this->childGroups)) {
-      $group = array_reduce($this->childGroups, function ($group, $child) {
-        return $child->apply($group);
+      $group = array_reduce($this->childGroups, function ($group, $child) use ($original_query) {
+        return $child->apply($group, $original_query);
       }, $group);
     }
 
@@ -147,11 +150,16 @@ class GroupOption implements QueryOptionInterface, QueryOptionTreeItemInterface
       return TRUE;
     }
 
-    // If any child Groups or their children have the id return TRUE.
-    return array_reduce($this->childGroups, function ($has_child, $group) use ($id) {
-      // If we already know that we have the child, skip evaluation and return.
-      return $has_child || $group->id() == $id || $group->hasChild($id);
-    }, FALSE);
+    if (is_array($this->childGroups)) {
+      // If any child Groups or their children have the id return TRUE.
+      return array_reduce($this->childGroups, function ($has_child, $group) use ($id) {
+        // If we already know that we have the child, skip evaluation and return.
+        return $has_child || $group->id() == $id || $group->hasChild($id);
+      }, FALSE);
+    }
+    else {
+      return FALSE;
+    }
   }
 
 }
diff --git a/tests/src/Functional/JsonApiFunctionalTest.php b/tests/src/Functional/JsonApiFunctionalTest.php
index 6da6396..9a6a0e5 100644
--- a/tests/src/Functional/JsonApiFunctionalTest.php
+++ b/tests/src/Functional/JsonApiFunctionalTest.php
@@ -336,45 +336,45 @@ class JsonApiFunctionalTest extends JsonApiFunctionalTestBase {
     $this->assertGreaterThanOrEqual(OffsetPage::$maxSize, count($collection_output['data']));
     // 5. Grouping grouped filters: Get nodes that are promoted or sticky and
     //    created by admin.
-//    $filter = [
-//      'and-group' => [
-//        'group' => [
-//          'conjunction' => 'AND',
-//        ],
-//      ],
-//      'or-group' => [
-//        'group' => [
-//          'conjunction' => 'OR',
-//          'memberOf' => 'and-group',
-//        ],
-//      ],
-//      'admin-filter' => [
-//        'condition' => [
-//          'path' => 'uid.name',
-//          'value' => $this->user->getAccountName(),
-//          'memberOf' => 'and-group',
-//        ],
-//      ],
-//      'sticky-filter' => [
-//        'condition' => [
-//          'path' => 'sticky',
-//          'value' => 1,
-//          'memberOf' => 'or-group',
-//        ],
-//      ],
-//      'promote-filter' => [
-//        'condition' => [
-//          'path' => 'promote',
-//          'value' => 1,
-//          'memberOf' => 'or-group',
-//        ],
-//      ],
-//    ];
-//    $collection_output = Json::decode($this->drupalGet('/jsonapi/node/article', [
-//      'query' => ['filter' => $filter],
-//    ]));
-//    $this->assertSession()->statusCodeEquals(200);
-//    $this->assertEquals(0, count($collection_output['data']));
+    $filter = [
+      'and-group' => [
+        'group' => [
+          'conjunction' => 'AND',
+        ],
+      ],
+      'or-group' => [
+        'group' => [
+          'conjunction' => 'OR',
+          'memberOf' => 'and-group',
+        ],
+      ],
+      'admin-filter' => [
+        'condition' => [
+          'path' => 'uid.name',
+          'value' => $this->user->getAccountName(),
+          'memberOf' => 'and-group',
+        ],
+      ],
+      'sticky-filter' => [
+        'condition' => [
+          'path' => 'sticky',
+          'value' => 1,
+          'memberOf' => 'or-group',
+        ],
+      ],
+      'promote-filter' => [
+        'condition' => [
+          'path' => 'promote',
+          'value' => 0,
+          'memberOf' => 'or-group',
+        ],
+      ],
+    ];
+    $collection_output = Json::decode($this->drupalGet('/jsonapi/node/article', [
+      'query' => ['filter' => $filter],
+    ]));
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertEquals(0, count($collection_output['data']));
   }
 
   /**