Slicer to filter two column without context

sonm10 

I created a new table combining Seller and Buyer with distinct values then created a measure that identifies if the selected values (One or more) is found then filters the table. Check the attached file

Exists = 
VAR __SellerBuyerSelected = VALUES( BuyerSeller[Buyer] )
RETURN
    CALCULATE(
        COUNTROWS(table1),
        Table1[Buyer] IN __SellerBuyerSelected || Table1[Seller] IN __SellerBuyerSelected
    )

Fowmy, Thanks for your solution. It is working as expected however, when we only have the buyer, seller and cost columns in the table, the silcer is not working. For that, I have added an additional field (although not required in that particular table) for the slicer to work.