bp_blogs_remove_user_from_blog( int $user_id, int $blog_id )

function bp_blogs_remove_user_from_blog( $user_id, $blog_id = 0 ) {
	global $wpdb;

	if ( empty( $blog_id ) ) {
		$blog_id = $wpdb->blogid;
	}

	bp_blogs_remove_blog_for_user( $user_id, $blog_id );
}