I have replaced parts no. 7 and 8:
https://www.realoem.com/bmw/enUS/sho...diagId=11_4773
07 Adjustment unit, inlet camshaft 1 11367583818
08 Adjustment unit, outlet camshaft 1 11367583819
In my case only outlet Vanos was suspected and was giving errors, but it was advised to replace both, however it was not cheap....