Etherdongle = 4 universes.
one universe on each of the 4 twisted pairs in the Cable connected to the output connector.
Hubs do 1 universe.
4 port Passive hub does universe on first pair, orange/white with orange stripe
Active hub allows selection of which universe, but only does 1 of them.
There is a combiner/splitter board.
In 1 pair 1 goes to out pair 1
In 2 pair 1 goes to out pair 2
In 3 pair 1 goes to out pair 3
In 4 pair 1 goes to out pair 4
Since there are no active components, the data can flow either from the in to the out or from the out to the in ports.