MDG Key Mapping Business partner

Hi, I have checked a couple of blog posts explaning how to figure out the link between business partner IDs in different systems (key Mapping). For example,

https://blogs.sap.com/2018/07/17/key-mapping-in-master-data-management/

However, I am still unclear what is the link between key id and object id with BP number in UKMDB_KEYBNSS0.

Could you please give me some pointers?