Parts in different tunes

I have to made a arrangement for brass-quartet 2 trumpets, trombone, tuba.
In Dorico I have the partitur and 4 single parts.

What I need is, this 4 parts to change in different tuned. For example - duplicate the 1st trumpet to 1st part in C, Eb, F. And the 2nd trumpet to.
If I duplicate in settings a player, Dorico make an empty sheet. that’s for me not duplicate.

is there anyone who know how it works?

Don’t add a new player. Add a new layout, assign the original player, right-click on the new layout (in the right panel of Setup mode) and click on Clef and Transposition Overrides. That dialog is explained on pages 46-48 of the Version History.