Using Dorico 4.0. I want to map Chords and Piano accompaniament to different OUTPUT channels using PT Stage, so I can mix the volume as I like. Any suggestions please? Thanks.

I use Dorico 4, so I looked into the options. I have two suggestions for you.

After creating the piece with a normal grand staff, I would create add another piano instrument, and cut the base clef from piano 1 and paste into piano 2. Then in the File >> Export >> Audio options, you have the option to export the audio for each instrument to separate files.

If the above solution is not what you are looking for, check the Steinberg Dorico Forum (https://forums.steinberg.net/c/dorico/8), which I have found to be very helpful.

Hope that helps
W