I pulled apart the diverter block which provides hydraulic pressure to my loader control valve. Photos are below. It looks like fluid simply comes into the bottom of the block, is diverted out the lower hole, returns via the upper hole and continues onward toward the 3PT hitch. I thought there might be a "tunnel" connecting the lower orifice with the upper one (which didn't make much sense to me) but upon inspection what appeared to be a connecting tunnel turned out to simply be the impression/dimple made by the drill that created the hole in the bottom/top for the rigid lines to connect to the box. I'm not sure that shows up in the photo. The side with the flex lines is pretty simple. It's just a plate with holes in it to which flex lines can be connected. In fact, the whole thing is very simple.
Sorry the photos are great. It was raining and pretty overcast so there's wasn't a lot of light to work with. Not to mention my camera/phone was getting rained on.