Nextcloud Talk: Define Groups visible for each user

Hi. I was very exited by NextCloud talk. Its a fantastic app. Thanks
I have one issue though. On our Server we have schools with students and teacher
We have also some business with workes, staff and administration

Issue I have is that the Students can see all the groups of the business.

I would have liked to narrow down so the people can only see the users and groups they are member of. In this way i can for each institution have a basic group for all at the institution and all member of this can see all in this group.

As I see it now i can only define what groups will see the talk feature but again this does not help us alot as still groups across institution will see each others groups and users.

I can see that all users across institution will be able to search each other but would be great if we got more control over what groups are displayed

Hope anyone has a solution or a valid comment
Thanks
Morten