Index: core/kernel/db/db_tag_processor.php
===================================================================
--- core/kernel/db/db_tag_processor.php
+++ core/kernel/db/db_tag_processor.php
@@ -2738,6 +2738,15 @@
 		$params['m_opener'] = 'd';
 		$params[$item_prefix . '_id'] = $object->GetID();
 
+		$parent_prefix = $this->Application->getUnitOption($object->Prefix, 'ParentPrefix');
+
+		if ( $parent_prefix !== false ) {
+			$params['pass'] .= ',' . $parent_prefix;
+			$params[$parent_prefix . '_id'] = $object->GetDBField(
+				$this->Application->getUnitOption($object->Prefix, 'ForeignKey')
+			);
+		}
+
 		if ( !isset($params['temp_mode']) || (isset($params['temp_mode']) && $params['temp_mode']) ) {
 			$params[$item_prefix . '_mode'] = 't';
 			$params[$item_prefix . '_event'] = 'OnEdit';