I’ve created custom post type “Services” with 'hierarchical' => true,. My loop is simple:

    while (have_posts()) {
      the_post();
      get_template_part('content', get_post_type());
    }

In admin I have next structure:

• Service 1
• Service 2
  • Sub-service

The problem is that on Services page I have all of them. But I want only 1 level posts without children posts. And children posts should be inside parent post. How can I do that?