Groups Module

Hello,

For EasySocial Groups Module, could you help me and said me how can I display only Groups whose logged-in user is not a member (not Join) ?
In other words, the opposite of the option "User Groups (Only display groups from current logged in user)"

In my opinion it happens in the file and the following area :
But how to reverse the function ?
/modules/mod_easysocial_groups/helper.php

		// Groups from logged in user

		if ($filter == 3) {

			$options['types'] = 'currentuser';

			$options['userid'] = $my->id;

			$groups = $model->getGroups($options);

Thank you,
Philippe