What is the hose that the clip is holding? Where does it come from or go to? Does that hose (see pic below with green arrows pointing to it) have the full 11 digit or shortened 7 digit BMW part nbr on it anywhere? If it does, it may help find the clip.
If that clip is holding a hose that is not associated with the power steering reservoir...then both may be in another diagram even though it is mounted in the reservoir.
For example (not saying this is it)... BMW part #
34306766380 (
#19 in the diagram below) is a "holder" that is used to support sections of the brake pipe lines.
And BMW part #
11667553769 (
#6 in the 2nd diagram below) supports the fuel tank breather valve line. Since #6 in the diagram below looks a lot like what you have circled in your pic...that piece is called a
"holder". You can take that tidbit and use it as the search word on the realoem.com website...type "holder" into the part nbr/name search box and see all the diagrams that have a holder in it. Narrow down to areas that would be in the engine bay and that would be supporting the hose/pipe/line you have pictured...perhaps you can find it that way.
