Monitor Water Level in Tank with Door Sensors

I have a tank of water that I am using to provide water to chickens. Im working on a way to monitor the water level. I have installed two door sensors on the outside of the tank with wires attached the contact blocks…these wires are glued to the inside of the tank at 10% remaining and 50% remaining. They are toggling on an off with water level. What I would like to do is integrate the digital readings from these two sensors into a SmartApp or Device Handler so that I can look at status without looking at the individual sensors. IE…if the 50% sensor is ON display >50% remaining, if the 10% sensors is On display >10% remaining. What is the best way to go about this - seems simple but I havent found a good example integrating multiple simply devices into a status.

Create a virtual dimmer… have both sensors update the dimmer “brightness”.
Ie: if sensor1 and sensor2 are open set dimmer to 5%
if sensor1 and sensor2 are closed set dimmer to 75%
Ect, ect…