You'll always need to be able to split signals and feed the same signal to different modules. This is a 1 to 8 un-buffered multiple, mechanically connected in a pretty smart way using switching jacks. It can be used as: 1 x 1 -> 8, 2 x 1 -> 4, 1 -> 5 & 1 -> 3, 4 x 1 -> 2, and so on... It's un-buffered with all the pros and cons that comes with un-buffered connections between multiple modules...
Unfortunately there are no building instructions for this module, but at least you'll find the schematic, some photos, and some comments.
The multiples finished, but not yet mounted in the modular
That's it! Have fun and split your signals!