Can I use the same waypoint more than once in a trip?
A single pin can only be set as a waypoint once, but you can add an additional pin at the same location to create a route with the same location multiple times. One easy option is to drop a new pin near the original with a long press on the map. You can press and hold near the middle of these purple dropped pins to drag them and precisely place it near the original pin location (the pin drops where the sharp bottom is located when released).
After adding it to your route, you could use the same pin name as the original pin, e.g. “Hotel X”, by changing it on the pin’s details screen (tap the map pin, then tap the popup that shows name/ETA).
Since these two pins are next to each other but you don’t want to visit them in order, disable “Optimize Waypoint Order” under the Route button and instead drag the waypoint up/down in the list to reorder it.