curl --request GET \
  --url https://api.opal.dev/v1/groups/{group_id}/containing-groups \
  --header 'Authorization: Bearer <token>'

{
  "containing_groups": [
    {
      "containing_group_id": "7870617d-e72a-47f5-a84c-693817ab4567"
    },
    {
      "containing_group_id": "50333e67-73ce-47ab-b049-d8abcd45f7a1"
    }
  ]
}