The Mono Switch block routes an input signal to one of many possible outputs, the strip of radio buttons is used to select an output (each radio button corresponds to a coefficient RAM parameter).
To begin, drag the block into the workspace, right-click it and select Add Algorithm > IC N Mono/Slew or Mono. (The result appears the same.) The Mono/Slew algorithm lets you rapidly ramp the source level up and down without any clicking noises when switching outputs. It uses N hardware volume controls in the target/slew RAM to do its job.
See the Multiplexer/Demultiplexer Example utilizing this block.
The default block is ready to use as a 1×2 connection, and like the others can be grown by right-clicking and selecting the desired number of outputs. The example below has been grown by 3: