First, what’s the full model number of your tractor, sometimes it matters? There’s a plate on the frame, maybe left front. Do you have HST, power steering, cab?
Kubota uses several different hydraulic tie-in schemes. I think yours uses one of the simplest ones. There should be a hydraulic block under the right side floor near the brake pedals. The block contains the pump relief valve and a diverter valve with a lever or screwdriver slot. There will be 2 or 3 plugged ports (3/8 pipe, I think) where auxiliary valves can tie in.
There’s a WorkShop Manual available to download at
www.kubotabooks.com for free. Looks like yours is in several sections. In the hydraulic section is a diagram of the hydraulic system and information on the block. The important thing to remember is this is an open center system, which means the fluid flows continuously through the whole loop until diverted by one of the valves to a cylinder (or other use).
You could use the factory valves if they’re still available, but they’re expensive. I’m sure TheOldHokie can advise on a more economical solution.
Can you post a few pictures of your hydraulic block?