Staff Labelling problem: trombones

What it looks like:
WhatItLooksLike.png
What I want:
WhatIWant.png
How?

Can’t do group names yet.

Well, you can fake it. Name them alto, tenor, etc. Set indent to higher value. Add text “Trombone” and drag in engrave mode.

Or set the name of the middle staff as Trombone [spaces] tenor…