How to treat substitutions in BOM

Hello, all.
I am building the BOM for electronic board. Several different items (different name, supplier, manufacturer) can substitute one another. For example, some capacitor of 5uF-5V may be chosen from supplier X1 of manufacturer M1. But this capacitor, with the same characteristics, with different item code may be bought from supplier X2, manufactured by M2.
Both items are in the stock base and for me there is no difference which one to use.
How to treat this case in BOM?
Especially in the case when both items exist/absent in the stock?

Thanks a lot for the help.

Sorry, it appears to be the feature already in PR.
Waiting impatiently for implementation…