Hi,
there is is no such a link. The fields of authorization objects can't be directly mapped to the database fields. The logic is built into applications. For example object M_BEST_BSA. It controls access to PO based on document type. Just giving authorization for this object is not going to give access to all POs. There are additional checks performs such as if user has access for a site and so on. There might be some more objects that control access on more granular level (e.g. access to pricing on PO).
In your case we are talking about vendor which can be modified in transaction XK02. So you can see a list of all proposed object for this transaction in SU24. The object F_LFA1_AEN might be interesting for you. You can get more info about this object in SU21.
Cheers