BuddyPress.org

Put this code in your bp-custom.php or child theme’s functions.php


add_action("init","bpdev_remove_author_link");
function bpdev_remove_author_link(){
global $current_blog;
if($current_blog->blog_id==12)
remove_action( 'bp_adminbar_menus', 'bp_adminbar_authors_menu', 12 );
}

I hope that should do it.
You can change that 12 to any blog id in the line if($current_blog->blog_id==12)