That hose is part of the oil cooler piping. No aftermarket option is available so you'll have to get the replacement at a dealership (Nissan part number 21306-JP00A). If you replace the thermostat at the same time and move the coolant reservoir out of the way it should help with gaining access to that end of the hose (...the other end connects by the oil pan). Your radiator hoses look like original equipment--you should consider replacing all of them given what happened.My car recently lost all the fluid and overheated… it looked like everything was in tact until I filled it with water and found it leaking from this hose.
It’s not one of the main radiator hoses so I’m not sure what it is, or what to even search for, I can’t find it in a diagram. If anyone knows what to search for or a part number or even better a link, I’d much appreciate it! Also not looking forward to changing it; they sure don’t leave much room to work on this car… 🤦♂️