get additional property

kernel/EntityRelation.php

@@ -190,12 +190,15 @@ class EntityRelation
     {
         $relations = $this->getEntityRelationsBySlug($entity);
         if ($relations){
+            $relationsArr = [];
             foreach ($relations as $relation){
                 $moduleClass = $this->getAdditionalPropertyClassBySlug($relation);
                 if ($moduleClass and method_exists($moduleClass, "getItems")) {
-                    return $moduleClass->getItems($entity, $model);
+                    $relationsArr[$relation] = $moduleClass->getItems($entity, $model);
                 }
             }
+
+            return $relationsArr;
         }
 
         return [];