Yes, do not confuse a splitter with a switch. A splitter takes a one signal and splits it into two signals of the same.
A DiSEqC switch or 22kHz switch is an electronic switch. It takes an input from the LNB(f) 1 or more, and switches it to the output.
So if you have say 4 LNB(F)'s wired to a DiSEqC switch, you can set things up in the receiver and it will send a command down the same coax, to tell the switch, which one to select.