I have a piano piece I want it to be tow player, Not a group. For example
P1 triple stave
P2 Base stave
You could add a second piano player, copy the bass staff’s music from the 1st to the 2nd, delete it from the 1st, and hide empty staves (with a particular eye on step 5). Or, remove the bass staff from the 1st player and the treble staff from the 2nd player. Or, don’t add pianos at all - instead add e.g. a violin and a cello (that have a single treble and bass staff respectively) and copy whatever needs to be copied, and manually handle changing the sounds loaded into the relevant endpoints for playback.