Summary

3 push buttons for parallel combination of two resistors.
Position 1: S1on+S2on (both resistors in parallel)
Position 2: S1on+S2off, (first resistor connected)
Position 3: S1off+S2on. (second resistor connected)

Used for switching 4ohm and 8ohm power resistors in dummy speaker load. Positions correspond to 2.7ohm, 4ohm, 8ohm.

Designed for regular 32mm rocker switches.