See also the Transaction response object.
This functionality is specific to Braintree Marketplace merchants.
$result = $gateway->transaction()->releaseFromEscrow("transaction_id");
If the transaction can't be found, you'll receive a
When you release a Braintree Marketplace transaction's funds from escrow, we'll disburse the service fee less any processing fees to the master merchant account and the remaining funds to the sub-merchant. This occurs on the business day after you submit the release request.
escrowStatus of a transaction must be
held before its funds can be released from escrow.