That works thanks. And I also made the avatars sync across the network. But what about the covers?

What are the equivalents of “bp_core_avatar_upload_path” and “bp_core_avatar_url”, for profile avatars?

I’m using this:

/***sync avatar across multisite network***/
function bpdev_fix_avatar_dir_path( $path ){
   if ( is_multisite() && BP_ENABLE_MULTIBLOG )
       $path = ABSPATH . 'wp-content/uploads/';
   return $path;
}
add_filter( 'bp_core_avatar_upload_path', 'bpdev_fix_avatar_dir_path', 1 );
//fix the upload dir url
function bpdev_fix_avatar_dir_url( $url ){
  if ( is_multisite() )
      $url = network_home_url('/wp-content/uploads') ;
  return $url;
}
add_filter( 'bp_core_avatar_url', 'bpdev_fix_avatar_dir_url', 1 );