BuddyPress.org

You can create a nwew page in the wp backend and use a custom template for it (you can find information on how to do that in the wordpress.org codex). At the top of that template file (before the function get_header()) you can put something like this:

`global $bp;

if( ! is_user_logged_in() )
bp_core_redirect( $bp->root_domain .’/’. BP_REGISTER_SLUG .’/’ );`