Using Inactive Relationship to Fill Gaps in Data

Anonymous add a new column like this as an example for a vendor. 

In my example, the Customer represents your Contract Header table and the Table represents your data table.

Vendor 1 = 
VAR __vendor = RELATED ( Customer[Vendor] )
VAR __vendorIfBlank = 
IF ( COALESCE( __vendor, "" ) = "", 
    MAXX ( 
        Customer, 
        CALCULATE ( 
            MAX ( Customer[Vendor] ), 
            USERELATIONSHIP ( Customer[Column1], 'Table'[Col2]  ) 
        ) 
    ),
    __vendor 
)
RETURN __vendorIfBlank 

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