I don’t think macOS allows selecting two or more devices here.
But if your goal is to send audio output to more than one device, there’s a built in utility called
Audio/Midi Utility. In that, you can create a new
Multi-audio device within which you can pick multiple devices. Then in this menu you can just select that one device.
I think Michael just wants to switch between two devices.
There is a little macOS utility that can do that and which can be called from BTT:
After installing this with brew (https://brew.sh ) you can use the "Run Terminal Command" action to jump to the next device:
I totally missed the
between in his title. My bad.