OK, I think I get what you mean now. You want to control one device (have focus on a single device) and from that be able to control the inputs multiple Hydras (for example.)
This is an idea that has come up various times in various guises, probably most well known on the forum as dBlue’s Doofer Device. As yet no dedicated device exists (the main idea is to be able to consolidate parameters you want into a single device, which can be the only one maximised visible and only one you need to control to access multiple effect.)
BUT I did find a work around for doing this. Although I can’t remember exactly how Duplex works with respect to giving you control of which parameters of the selected device this tip might still give you an idea.