Sonos Party Switch

You will need the CORE smartApp installed and it will require a little investment of time on your part if you are not familiar with it. Luckily, there is a lot of help available on the forum. Keep in mind, there may be a simpler solution or smartapp available but this is what I would use since I already have it configured for any custom automations I need. I well worth the time to learn because the possibilities are endless when you understand its potential. See links below.

For a quick tutorial see:

And for help if you get stumped: