This is one of over 4598 effects generated by Filter Forge, a Photoshop plugin that allows you to create your own filters.
To open this filter, you must have Filter Forge 1.0 or higher installed on your computer. If you don't have it installed yet, click here to download Filter Forge
Ok, "switch" function is well understood, but seems that we can just use a checkbox if we have just 2 entries. It's enough sending one in channel 5 and the other in channel 8. This is not written in "switch help" but check it out ;)
switch, trasparent, transparent, two, 2.