BuddyPress.org

try this one

define("BP_LOGIN_SLUG","login");

function bl_setup_component(){

bp_core_add_root_component( BP_LOGIN_SLUG );

}

add_action( 'bp_setup_root_components', 'bl_setup_component', 2 );



//handle the screen

function bl_screen_handler(){

global $bp;

if ( $bp->current_component != BP_LOGIN_SLUG) )

return;//return the control back



if(is_user_logged_in())

bp_core_redirect(bp_get_root_domain());



//load template

bp_core_load_template("/registration/login",true);

}

add_action("wp","bl_screen_handler",3);

Put a template file login.php with the form in your registration folder and it will work as you have mentioned.