BuddyPress.org

I have installed buddypress and now want that all users/members except admin should be redirected to groups page after login. I have written the code in a file mu-plugins/bp-custom.php

<?php
add_filter("login_redirect", "bp_my_groups_redirect",10,3);
global $user;
function bp_my_groups_redirect($redirect_to_calculated,$redirect_url_specified,$user) {
	if(empty($redirect_to_calculated))
	{
		$redirect_to_calculated=admin_url();
	}
	setcookie("bp-groups-scope", "personal");
	/*if the user is not site admin,redirect to his/her groups*/
	$user = wp_get_current_user();
	if (in_array( "administrator", $user->roles ))
		//return $redirect_to_calculated;
		return admin_url();		
	else
		return "/groups";
} ?>

But, now all the members are getting redirected to groups page along with administrators. I want to redirect the administrators to wp dashboard. Please let me know the correct code. Please help.