The profit and loss and balance sheet of CBA are calculated by reference to Australian Accounting Standards, not APRA's prudential standards which you referenced. APRA sets minimum capital standards and sets out how risk assets should be calculated but APRA does not determine how assets are valued on a bank's balance sheet as you stated.
As to CBA they also have a $27b asset associated with those derivatives, so a net valuation of a few billion. Most of the derivatives are vanilla FX and interest rate instruments and straightforward to value. In terms of market risk, CBA runs small positions so is unlikely to lose much from that. There is credit risk associated with counterparty default but most are subject to netting agreements and cash collateralisation significantly reducing the risk.
Are you suggesting the asset and liability should be higher? On what grounds?
