Sending Text to 5 scenes(on the server) 5 people interacting / 5 people mirroring.

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Hello,
In unity, I have a project with a 'main scene' which is sending Text to 5 different scenes (Group A). Those scenes can see that text but also interact with their own scene. On top of that there are 5 more people ('Group B') who don't have to interact with anything but they must see everything that is on Group A's screen.
A picture might help: https://imgur.com/a/Iy6PwPv

I'm not sure where to even get started or what the design of this system would be.
Can all of this be done by the server. everyone connects to the server and some interact and some don't interact but still see the same information?
Can group B see a 'mirror' of Group A? or does group B have to send back all the information to the server which then can send out 5 scenes to 5 more clients? (Server to Group A -> back to server -> 5 other clients?)

I'm very confused and my project is due in a couple of days. please help!
Thanks so much!