How do you search for hotels that rent rooms for a few hours at a time any time of day? I see them around Taiwan and have used them but don’t know how to search online for them.
Not looking specifically for love motels. Looking for a search method to find any type hotel where someone could go rest for a few hours in the middle of the day.
sure, buddy 
IIRC (it was a long time ago) the last time I tried to find a nice motel, I had the same problem, but Google Maps did the job. Just browse around the relevant area and they’ll be marked, with links to their own websites. Things might be different now, but at the time I couldn’t find a booking site that specialised in motels.
Even if you’re not looking for a love motel, they’re basically the only ones that do <1 day rooms. None of the mainstream ones do (at least not at anything less than rack rate).
Found one site/app that has short stay (couple hours) hotel listings.