The Midi Matrix (Channel Filter) is a 3-in-1 filter plugin with a simple UI
enabling you to easily accomplish:
* MIDI channel filtering (e.g. blocking of specific channels)
* MIDI channel multiplication (e.g. send events from channel X to channels
  X, Y and Z)
* MIDI channel rerouting (e.g send events from channel X to channel Y)
* And any possible combination thereof

WWW: https://open-music-kontrollers.ch/lv2/midi_matrix/