Table BBPM_BUT_FRG0061 contains 'Purchasing data', e.g. currency, payment terms.
In order for SRM to 'find' this data for specific business partners (e.g. vendors, bidders,..) multiple tables are linked with each other.
The 3 fields you mentioned could be used as follows:
Table BBPM_BUT_FRG0060 contains 'Purchasing (Admin)' data. This table is linked to
a) Vendor record - VENMAP for vendors from SAP ECC
b) Purchasing data - BBPM_BUT_FRG0061
The following fields of BBPM_BUT_FRG0061 are:
- Entity Guid: Link to BBP_BUT_FRG0060
- BP Guid: Link to VENMAP and/or BUT000
- Record Guid: Guid to make the record 'unique' (though I am not quite sure about that).
Above is my interpretation of these fields.
Each guid is related to some or other table
record_guid : It is the primary key to fetch entry from table BBPM_BUT_FRG0061
entity guid : it is the primary key to fetch table data from table BBPM_BUT_FRG0060
bp_guid : It is used to fetch entry from table but000 related to partner details