Dunning letter with multi-groups based on a single query data source
How to add a parent group in the Dunning Letter that based on a single query.
The answer is obvious if XML report/letter is based on the Oracle Report with groups pre-defined (like Dunning Letter was in 11i), but what if it is just based on a single query (like Dunning Letter in R12)?
For instance, we have a standard Oracle pre-defined query and a template in Oracle Collections for the Dunning Letter that is based on a single query that have 1 cursor (payment_history) but we need to create/display on the template another group above that one (currency or debit/credit).