Single pole to a 3 way?
I doubt you will find one. For simplicity (fewer SKUs), you will generally find "everything the same". So that would mean "3 regular switches" or "3 3-way switches". But due to box fill limits (see Looking for triple 3-way switch ) plus I suspect limited demand to figure out a solution, a triple 3-way doesn't seem to exist.

What might work is a smart switch. Many smart switches have "remotes" that are either battery powered or just use a few wires to get power, control power and communicate to other switches. But in a quick search I didn't see any single gang triple switches.