Hi @lakshmim85,
You can have logic at persist delegate() at cache inserted block to fetch custom field and assign it to Grid field. Please find the sample code below for your reference.
public class CADepositEntryExtension : PXGraphExtension<CADepositEntry>
{
public delegate void PersistDelegate();
[PXOverride]
public void Persist(Action del)
{
if (Base.Document.Cache.GetStatus((object)Base.Document.Current) == PXEntryStatus.Inserted)
{
foreach(var paymentrecord in Base.DepositPayments.Select())
{
// Write a logic to fetch the custom field value based on the Payment Type and Reference Nbr and assign it to grid field.
}
}
del();
}
}