BuddyPress.org

Hi Venutius, thank you for your reply! I meant the file, inside the buddypress files directory (screenshot: https://ibb.co/bgFfSgr).
About you’re saying:

Also I’d load it in the action hook ‘bp_setup_nav’, not ‘wp’.

Did you mean changing the line
add_action( 'wp', 'groups_subnav_hook', 2 );
to
add_action( 'bp', 'groups_subnav_hook', 2 ); ?

Thanx very much for help (y) !