This is a more compact version of button selector panel i just made a thread of a couple seconds ago. It does basically the same thing but its just a lot more compact and small.
Here is a photo:
Have you observer on this version ? (I'm on java, I don't know about other version^^)
if yes, you can do this after all buttons :
sticky piston -> observer -> air -> sticky piston -> redstone block -> air -> lamp
I like trains... OF CHAIN COMMAND BLOCKS !
yes we do have observers on this version. thx for the idea no i wont steal it