As a manager of a Groupsite, you have the option of "hiding" any activity that appears on a Recent Activity module by simply clicking the "Hide this activity" button next to the action.
A Groupsite member can hide only his/her own activity.
Any activity that you hide will also not appear in any Recent Activity notices that are emailed to members.
You can hide an activity either from the Recent Activity module (shown above) -- or, by going to the "Recent Activity" area located in your actual profile:
1) Log in to your Groupsite.
2) Go to MY SETTINGS > MY Profile.
3) In the General Information area, click the "View My Profile as Others See It" link
4) Scroll down to your "Recent Activity" section, and then click the "Hide This Activity" link, to the right of the action you want to hide.