use RainLab\Blog\Models\Post as BlogPost; function onStart(){ //This is where you list the categories you want to display $categories = ['cat-a','cat-b']; $posts = []; foreach(BlogPost::all() as $blog){ foreach($blog->categories as $cat){ if(in_array($cat->slug, $categories)) { array_push($posts, $blog); break; } } } $this['filteredPosts'] = $posts; }