Can a DPDT switch be used in reverse so that it selects 2 of 4 inputs to go to the 2 outputs?
There are not really &quot;inputs&quot; and &quot;outputs&quot; on a switch, but if you arbitrarily call the contacts &quot;inputs&quot; as shown below you have situation shown:-



simulate this circuit &ndash; Schematic created using CircuitLab
If you need to independently select 1 or 2 vs. 3 or 4 then there are 4 combinations and you can use 2 SPDT switches.
If you want be able to select any of the 4 inputs to either of the 2 outputs there are 8 possibilities and you'd probably end up using a multipole rotary switch.