I have troubles with adding my application to group for any test user. I've created two test users and one of them has group and he is an admin there and I wrapped those users into test application.
I've added two permissions for groups (groups_access_member_info, publish_to_groups). In user settings I see my application but in group settings I can't add my application.
I need this because I would like to make request from facebook graph API.
Regards
In order to test the Groups API with an app in development mode, you need to be an admin of both the app and group. Test users don't count as admins of the app. Therefore, you'll need to use a real user account. You don't have to add the app to the group, it is assumed that the app is added if you are the admin of the group.
Source: Facebook Platform Bug Report.
Additional information from another useful bug report: