To add yourself as a owner of a group, you will go to the group and select:
  1. Roster
  2. Manage
  3. Click Owner next to your name
Now when you go back to the Settings of the school form >
  1. Click Recipients
  2. Add
The Group dropdown will now display the group you just added yourself as an owner to.

Alternatively, if the Group is a Community Group using a Smart List, being the owner is not relevant.
Instead, you must be included as a natural result of the Smart List criteria.
This can be accomplished by adding yourself into the criteria by name, as with this example: