It’s always possible somebody somewhere has posted a wiring diagram on a forum in response to a request, but generally I would think the odds of finding one are pretty low. The best thing to search in Google for (if you haven’t already tried) would be the words, wiring diagram, or wiring schematic, followed by the model number of your appliance ( Where to find the proper model number and serial number on a washing machine ). There are some repair manuals being sold but these are very general and not model specific and written by third parties. All the ones I’ve seen are very much out of date although they may well still contain some useful general advice and knowledge.
Providing water level indication eg, by using a dishwasher pressure switch to activate LEDs or lights to indicate the water level in a tank. By using two dishwasher switches and adjusting their individual set-points, it's easy to have six levels indicated. However, you'll need a lot of wires to connect the switches to your display.