If the Ray is playing tv audio or music you can just long press the play/pause touch control on the Ones for them to group.

To group through the app, see the following support article:

https://support.sonos.com/en-us/article/group-and-ungroup-rooms

Unless you mean you want to use the Ones as surrounds with the Ray.

If that’s the case, separate the Ones from being in a stereo pair (option available in their room setting)

The Ones will then show in separate rooms. Go to the Ray room settings and select Add Surrounds.

Brilliant - that’s what I meant! Thank you