I believe what you have pictured is a dirverter valve specifically designed to replace the transfer cover on the top of the transmission housing in front of the seat, between your legs. Is this correct? If so one lever position should direct flow to the three point hitch internally. The other will direct flow to whatever you have hooked to it, such as an auxiliary valve. One hose should come out of the diverter to the auxiliary valve and back to tank. The diverter may have a return port on it, if not, I think there is a plug on th left hand side of the top cover, under the seat that can be used as a return to tank
PB is Power Beyond or or PBY, or sometimes called carry over.
PB is a port on some valves that with an adapter will pass the pump fluid downstream to another valve.
If you feed a remote valve, your remote valve should have a PB port and you add an adapter to make the PB port fully functional.
Look at your manual carefully and see if there is a pressure and return on the diverter for a remote valve.
On my Kubota, there is a switch for pump flow directly to the 3pt and another position for flow to the FEL then back to the hyd block, and then to the 3pt.
If there is an internal connection in the diverter block for the 3pt, you might have to bring the PB flow back to the diverter.
Either way, you should be able to use a remote valve.