Pretty sure the switch I linked to will do the job.
Three poles (common contact), each with 4 positions.
The switch can be used either way:
1 The "position" contacts could be inputs, feeding the "pole" contact as an output.
2 The "pole" contact could be the input, feeding the selected 1 of 4 "position" contacts as output.
Otherwise, I'm obviously not following what you need.