What’s the equivalent of Hide From Menus on MODX on WordPress?

You can create a Custom Field radio button called hide_from_menus with values yes or no t then use Query posts by custom fields.

Then in your query, add meta_key and meta_value. Example:

      $args=array(
        'post_type' => custom-post-type,
        'post_status' => 'publish',
        'posts_per_page' => -1,
        'meta_key'    => 'hide_from_menus',
        'meta_value'  => 'yes' 
      );

Be sure though that you update all your posts (re-publish) so that it will have the key value that you specified.