What if we could have a superuser network that could cut across network isolation?

What if we could have a superuser network that could cut across network isolation?

Scenarion:
- wireless 1: owner's network (superuser)
- wireless 2: a network for guests, with network isolation

Disired outcome:
- How can wireless 1 see devices on wireless 2?
- How can we ensure wireless 2 has no visibility of devices on wireless 1?

I want W2 guests to be able to access Sonos, lights, fans that would be on W2, but not devices set on W1. All this while enabling W1 (superuser) to see IoT devices on any network.