If the payment means are international account transfer and the account id is IBAN then the financial institution should be identified by using the BIC id.
//cac:PaymentMeans((cbc:PaymentMeansCode = '31') and (cac:PayeeFinancialAccount/cbc:ID/@schemeID and cac:PayeeFinancialAccount/cbc:ID/@schemeID = 'IBAN') and (cac:PayeeFinancialAccount/cac:FinancialInstitutionBranch/cac:FinancialInstitution/cbc:ID/@schemeID and cac:PayeeFinancialAccount/cac:FinancialInstitutionBranch/cac:FinancialInstitution/cbc:ID/@schemeID = 'BIC')) or (cbc:PaymentMeansCode != '31') or ((cbc:PaymentMeansCode = '31') and (not(cac:PayeeFinancialAccount/cbc:ID/@schemeID) or (cac:PayeeFinancialAccount/cbc:ID/@schemeID != 'IBAN')))