Where do we map buyer/purchaser to get sc's into SOCO

Hi Sap Gurus,

Can you tell me where is the relationship between SC's of a particular company code and Buyer maintained?

My question is if we create a SC (incomplete information) in Extended classic scenario that shopping will route to Buyer and from there Buyer creates a PO..... How the sc directly goes to that buyer inbox... where do we map this...

We do have different buyers but how particular shopping cart are going to Buyer 1 and some to Buyer 2.... Where is the relationship maintained?

Thanks in advance