To enable iCal feeds:
  1. Go to onCampus > Settings
  2. Select Group Page Options
  3. Select Activities
  4. Mark iCal Schedule

To view the schedule and export it as an Activity Group Owner:
  1. Select Groups > Find More
  2. Click the green iCal feed icon  calendar feed icon
  3. Copy the Webcal URL

To add that Webcal URL to an external calendar, follow the steps in Adding a Webcal Feed to my Device/Calendar