Yes.Just so I'm clear, we can't choose groups unless it's a group collaborating with another artist. Is that correct?
A group is identified as an artist like a singer is also identified as an artist, so it's fine to pick a group with an extra artist like your example. What we can't do is pick songs from just one group.
We can't choose Slade & Merry Christmas Everybody, but if they re-released that song after performing it with another artist like Suzanne Vega it would be eligible as a nomination.