this is an easy one!
Just get access to the water level switch located inside the control panel. There is a threaded screw which applies pressure to an air switch which controls the water level in the tub. If you turn the screw clockwise you will increase the pressure on the switch and thus raise the water level.
DO NOT GO OVERBOARD WITH THE ADJUSTMENT! Do it a small amount and see where that gets you. I would adjust it with clothes in it so you can see if it will be high enough. I think if you did it with an empty tub you would get the level you wanted but might just have the water level get too high once you added the clothes to it. Just want you to avoid any kind of leaks. So try it both ways and see what happens.
You should also "reseal" that screw when you are done with some candle wax or nail polish so it doesn't turn on its own or due to vibration.
Also, all the levels of your water will be higher once you make any adjustments to that switch.