My Z4 had Xenons which were adjusted by a switch behind the headlight. It was a real pain to get at since you had to get access from the wheel arch and feel for the switch. The 3 series has something similar but, I think, is accessible from the engine bay. The switch is a lever on the back of the headlight. Move up and down depending on which side of the road you are driving.
I would have thought the 1 series Xenons would have an accessible switch to select lhs or rhs driving.
With the Z4 I found the switch so difficult to find that I went down the dealers and got them to show me how to do it (at no charge I hasten to add). Once I had been shown it was relatively straightforward.
See my Topic elsewhere, but I quote...
"there are three suppliers for xenon headlights in BMW cars. Only one of them has the patented technology to convert from LHD to RHD. But these headlights aren't fitted into the BMW 1series so there is no way to switch sides with your headlights. "
I drive with my left hand drive in the UK since 1 month now, nobody ever flashed at me (I mean headlights, for the girls I can't tell you everything, but I don't think it is entirely related to the car )