Check if a user is part of an existing buddypress group

Buddypress-Group-Check.php

<?php
// check user against an existing buddypress group
// I needed this in a category.php file to see if
// we were looking at a specific category, and if
// so, check if the user is in a buddypress group 
// to ensure they should have access
if ( has_category( 'Some Category') && function_exists( 'groups_is_user_member' ) ) {
	$group_id = BP_Groups_Group::group_exists('buddypress-group-slug');
	$is_member = groups_is_user_member( wp_get_current_user()->id, $group_id );
	if ( !$is_member ) {
		wp_die( 'Unauthorized User' );
	}
}