It took me a second to figure this out. The documentation wasn’t terribly clear. So, I thought I would lay out the usage here for anybody else looking for the answer.
Basically, you need to connect some CHOP data into the Bind CHOP, THEN Turn on Binding(4th and purple thing in the param drop down), and reference the Bind CHOP’s channel using a Python expression.
An example would be:
Midi In CHOP -> (Maybe a Select CHOP to get the channel you want) -> Bind CHOP.
Goto the parameter you want to bind, Click on the + next to the parameter name, opens the parameter options(?), click on the the 4th and purple icon. Then type in the expression, assuming the Bind CHOP mentioned is at the same level and has the name bind1, op(‘bind1’)[‘chan1’].
And that’s it.