Workgroup Roster Visibility
As a Workgroup Chair or Administrator, you can choose to show or hide the group's roster. Choosing to hide the roster will remove the roster link from your group's dashboard. Please note however that users will still be able to see name and company of other users, as that information is listed next to content they have posted (such as documents).
To hide your roster, click on the Settings link on the top-right of your workgroup Dashboard:
Once on the Workgroup Settings page, select the radio button for "Only Administrators and Chairs", and click Save.