BuddyPress.org

a safe bet is just to modify a child theme for /groups/groups-loop.php and change the line of code
`

` to
`

`

another idea is just to add a forum link within the group directory loop
http://etivite.com/groups/buddypress/forum/topic/quick-tip-display-the-groups-forum-link-on-the-group-directory-groups-loop-php/#topic