Swapped out switch with three wires on the back and did not mark any wire!
Common and hot are not connected right because if I turn light on, it works but
Lights in other rooms on same floor do not! Have three separate sets of wires
In the wall behind light switch.. How do I find common wire?

Swapped out switch with three wires on the back and did not mark any wire!Why not? This is one of the most basic rules when doing this sort of job.

Aside from any ground, a 3-way switch has 3 wire positions and typically three wires. The travelers will almost certainly be coming from the same cable. The common is the other wire.

OK, so you changed out a 3-way switch and didn't note which wire was attached to which screw.
Are all of the wires that were connected to the switch in the same cable?
You said

Have three separate sets of wires
In the wall behind light switch
I assume that means three cables. Describe how those are connected.
Were any of those wires disconnected?