Вывод значений связаных инфоблоков

$arOrder = array("PROPERTY_prop2_1"=>"ASC", "PROPERTY_prop2_3.NAME"=>"ASC");
   
$arFilter = array(
   "IBLOCK_ID" => 25,
   "ACTIVE" => "Y"
);
   
$arSelect = array(
               "PROPERTY_prop2_3.ID", 
               "ID", 
               "PROPERTY_prop2_3.NAME", 
               "PROPERTY_prop2_3.PROPERTY_prop1_1", 
               "PROPERTY_prop2_3.PROPERTY_prop1_2", 
               "PROPERTY_prop2_1", 
               "PROPERTY_prop2_2"
            );
   
$res = CIBlockElement::GetList($arOrder, $arFilter, false, false, $arSelect);