There are instances when adding impacts, where you would want your club or group to be auto-selected for sharing purposes. e.g., if you made an impact to a club, and you were reluctant to share it with the University, even with the setting on, you may deselect it from sharing.
Note: This auto-share setting is only to help default the selection for data to be shared.
To default this setting, you may login and navigate to My Groups in the User Dashboard. For each group you are a member of, there is a menu of options enabling you to either always share your impacts, never share your impacts, or ask to share your impacts.