Yes - it's a hydraulic block, but I dunno which model(s) it fits. There are several variations of this on Kubotas. The two holes with o-rings are normally covered by a two-bolt cap, with passage that connects the two ports. It is intended as the spot where close-coupled factory hydraulics can be bolted. A block like the one in your pictures can be used instead for connecting remote hydraulics with hoses.
One port is the oil supply and would go to the inlet port of the remote valve. Regarding the second port, there's a good way to connect it and a not-so-good way. The good way is to connect it to the Power-Beyond port on the remote valve. This way the 3-point hitch will still work when the remote valve is in use. In this setup, exhaust from the remote valve goes to the reservoir in a 3rd hose. If the second port on the block is use for the remote's exhaust flow, 3-point hitch and the remote valve function will interact, maybe objectionably. But if you plan to strictly use just one at a time it would work ok.
