Limit User List by User Group

Easydiscuss is being set up to allow collaboration between a number of internal teams as well as registered members of the public. Each team has a number of members defined by their User Group in the ACL. They are only given access to Forum categories assigned by User Group. However, when they use EasyDiscuss they can list all Users on our Joomla site as can members of the public. There does not appear to be away to limit the list to only show users contained within their User group. Am I missing something?

Thanks..