Re-reading through the description of what you want to do here it seems like you don't actually want to create a cross talk thing. Seems more like you want to set up a dependency dial relation between 2 different, or multiple different dials, controlled by an over master (for lack of a better word) in the same figure.

The question is do you know how to set up a dependency?

Basically.

Create new master.

Toggle edit dependencies in that new master dial. This will bring up the editor.

Click start teaching and set the new master dial to 1. Don't hit enter, just click outside the number field on the palette and the value will be entered,  do this for every value you enter.. So now your master is set at 1.

Go to one of the dials you want controlled by this master. Set it to 1. Repeat for all the dials you want controlled by this master.

Return to the master dial and set as 0.

Return to all the controlled dials and set at 0.

Stop teaching.

If you want a master dial that  controls something at -1 also, it could be anything, another morph for instance, make sure you always return to 0 as a key, and then to -1. So don't just jump from 1 to -1. This might not be a necessary step in such a situation, but that's how I do it. It's a small step.

You can get fancy with values greater than or less than 1 controlling things also, blends and such. Activating a New JCM beyond a certain rotation point, etc.

Set desired limits and tracking scale in the dials settings. 0.02 is a standard tracking scale that's snappy. 1 is a very fast dial. ON/OFF almost.

Try to keep all your names between masters and slaves consistent. And whatever you do don't have multiple untitled morphs. Consistent naming helps narrowing down issues with complex dial set ups and makes things less confusing when sorting through tons of morphs for injection export.