This is the relay or switch. Logically a relay since the driver window can be remotely controlled.
Have you tried to use the auto down function of holding the door key in the unlock position until all the windows roll down ?
As you can see from the diagrams if you have power for up you have power for down. I marked the suspect trace with yellow.
Since BMW would never repair the inside of a module I suspect they simplified the diagram.
Internally there is almost certainly a switch that is probably a single pole double throw switch that hits the double throw relay so you would have the down side of that wiring to look at as well.
If the switch doesn't work but you can roll down the window with the key it's the switch that's broken.
If neither works it's the relay.
In either case swapping the door module from a parts car should fix the problem.