If you need to make some small CSS changes – place them in  Theme option   General   Custom CSS .

If you use Rehub without bundled child themes and want to add deep customizations, use blank child theme which you can find in full theme bundle or download and install rehub-blankchild

If you use one of bundled child themes (Rewise, Repick, etc) and want to add customization to such site – use rh-grandchild-plugin (RH Grandchild). Just install it as any plugin. You can do this from  Rehub   Plugins . This plugin works in the same way as child theme works for main theme. You can overwrite theme functions, and core files. To add custom functions – add them in file rh-grandchild-func.php (available from admin panel, find it in  Plugins   Editor ). All functions from this file will be added inside functions.php of theme, so, it’s the same as you add code to functions.php. You can also add some css and js in plugin’s files. For this, also uncomment (delete “//” in beginning of line) in file rh-grandchild.php this string:

//add_action( 'wp_enqueue_scripts', 'rh_grandchild_style', 11 );

If you need to overwrite core files from child theme – just place them in plugin folder in the same way as they exist in child theme. So file /inc/parts/query_type1.php must have the same folders inside plugin’s folder to overwrite file.