Post loop – Additional query arguments

Hello, dear! I’m using sydney theme on my site. I have some posts each of them have different categories, for example “appartaments ” and “for rent” or “villa” and “for sale” I want to build a request to show only post, which include several categories.

query_posts( array( 'category__and' => array(2,6) ) );

How can i realize it with Build Post Query Widget?
It would not work If i put in the field Additional query arguments

category__and => array(2,6)