I found the same parts, plus the plastic valve portion in my wife's 2004 X5 4.4 with 60k miles. It is the non-return oil check valve that prevents oil from draining back while the engine is shut off. Upon inspection, I could see where it was originally pressed in, inside the passage at the top of the filter housing. There is a service bulletin for this problem from 2005, stating oil pump replacement as the fix. BIG $$$ and lots of time, especially if you plan to tackle it yourself.

I contacted the service manager at Brian Jessel BMW here in Vancouver. He looked into the issue and promptly responded, according to BMW's recomendation, no action is required beyond removing the 4 components of the valve. No harm will occur as a result. If I wanted to proceed with the pump replacement, the pump is nearly $900 and the total job aprox. $3500 CDN dollars.

I could be wrong but historically engines didn't have this type of valve and oil drain back has always been a reality in those engines. Over time, the lack of instant lubrication at start up could shorten engine life by introducing added wear. I suppose time will tell. I would bet, most of these engines have had the valve parts removed and tossed at some point, with or without the owners knowing when servicing is being performed, especially if they were discovered during the warrantee period by a dealer.