Hi.

During the fill turn the timer off. Does the water stop?
If it does, drain the water out, then remove the clear hose from water level switch, see if there any holes in it and if not, blow in to it to clean any possible restrictions. Reattach and check.
If it's still overflowing, turn the washer off and check continuity at the water level contacts V and T.(With tub full).
You should read less than 1ohm.
No continuity - replace the water level switch.

The water level Part number: W10335056