I have a parent theme with two textdomains: parent_backend_domain, parent_frontend_domain. Now I do have a childtheme with its own textdomain: child_domain. I somehow cannot get it to work, that the localization of all three domains are used with the child theme. Can someone please help me what to put in my functions.php? I tried
load_child_theme_textdomain( 'child_domain', get_stylesheet_directory() . '/include/languages/' );
load_child_theme_textdomain( 'parent_backend_domain', get_stylesheet_directory() . '/include/languages/' );
However, somehow it always gets mixed up and not all the translations are used. Thanks a lot.