I have no idea what your instrumentation is, but let’s assume for a second that it’s a string quartet.
You have
Violin 1
Violin 2
Viola
Cello
Each of these has a part layout, and there’s also a score layout.
In Setup Mode, right click all the players and Duplicate. Move the extra players into a group, just for clarity.
Over on the Layouts panel, you’ll want to right click on your score layout and remove the duplicate instruments from there, but add the duplicate instruments to all of the part layouts.
So your Violin 1 part Layout will need the duplicated Violin 2, Viola and Cello players, for example, and your Cello layout will need the duplicated Violin 1 and 2 players and the Viola player.
Then go to the full score layout and head into Galley View. In Galley View it should be possible to see the duplicated instruments, even though they’re not in the full score layout. Cue (shift-U) from your real instruments into your duplicate instruments, wherever you want the full score excerpts to appear.
Then there’s some tidying up that you can do - with the cue selected, look down to the properties panel. You can do clever stuff like making the cues bigger than standard, and basically make it look like normal score.
Then you should probably head into Layout Options, Shift-select your various part layouts, and set Hide Empty Staves to All Systems - this will hide your duplicate instruments when there’s nothing cued into them.
You’ll probably need to fiddle around with the Layout Names, which will automatically update to reflect the fact they contain these various other staves, but I won’t get into that at this point - right now I have no idea whether the rest of this is what you need!
I should say at this point that I’m expecting that ALL players will need the full score for the same sections of music. If that’s not the case, you’ll either need way more of these duplicate players or a totally different solution.