Insert here the set of "Nested Parties" (firm identification "nested" within additional repeating group) fields defined in
"Common Components of Application Messages"
Used for NestedPartyRole=Leg Clearing Firm/Account, Leg Account/Account Type
For FX Futures can be used to express the notional value of a trade when LegLastQty and other quantity fields are expressed
in terms of number of contracts - LegContractMultiplier (231) is required in this case.