Need the joining table for Manage contract types columns buyer role and seller role

Summary:

I need the joining for

OKC_CONTRACT_TYPE_PARTIES for buyer role and seller role as I am getting whole data for the roles but I need to get only buyer and seller role based on contract type please refer below screenshot for your reference

Content (please ensure you mask any confidential information):

select OPAB.NAME,
CASE
WHEN okch.INTENT = 'B' THEN FLV.MEANING
END AS "Buyer",
CASE
WHEN okch.INTENT = 'S' THEN FLV.MEANING
END AS "Seller"
from okc_contract_types_b okch
LEFT JOIN OKC_CONTRACT_TYPES_VL OPAB ON OPAB.CONTRACT_TYPE_ID=okch.CONTRACT_TYPE_ID