You probably have a 5 input, 8 output, Terk multiswitch. The 5th input is for an OTA antenna. The OTA will appear on every output line. However, you have to put a dilpexer on each line that you want to see OTA.
You put the diplexer, which splits the satellite and OTA signals, on 1 line at each location that you want OTA. The diplexer ihas 2 outputs (marked) 1 for Sat and 1 for antenna (OTA).