What the warning looks like
The symptoms are an adaptive headlight malfunction warning, lights that do not turn with the steering, and one daytime running light ring the wrong color or out. The page covers E9x and E8x xenon AHL and F3x adaptive LED. See Adaptive Headlights / AHL Module.
Module, stepper, or the whole lamp
The page is thin because the quotes are different jobs: a whole adaptive headlight, coding or programming, stepper motors, a control module, and a shop range for a headlight or tail module. Ask which of those the quote is. A dealer tech in one source called a high coding figure high, and another note says programming alone is a smaller job if you install the light yourself.
Water, and what does not fix it
The notes say water in the housing often kills the module. They also say turning the lights off Auto disables the swivel but does not fix a failed motor. Dry the housing and find the leak before paying for a second module.
This is not a sunroof leak. Water on the headliner or the floor after rain is the BMW Sunroof Drain Clog and Wet Floor. A parking sensor warning is the BMW PDC Parking Sensor: What It Is and What It Costs. A tire pressure monitor malfunction is the BMW TPMS Warning and Sensor Replacement.
Which cars
Chassis named on the page are the E90, E82, F30 and F32. The E90 model page is BMW E90 repair costs and the F30 page is BMW F30 repair costs.