One group per two fields

[nova]

I have a report with multiple grouping, but would like to have the main,
upper group to be based on 2 fields, i.e. if a value appears in one of two
columns, then the record must be shown under 1 group. Is that possible? If
so, how?
In practice: the report is based on a query with records on seller-buyer
relationships, each with different values, comments, currencies, etc. I need
to show a report grouped by company that either occur as seller or buyer.
II's ok if the report will show duplicate records. That's actually the only
way I see this is possible: to duplicate all records and make each buyer a
seller to finally group by seller only. Just wish there is a better way...

 

[nova]

in case someone is interested in 'a' solution: I fixed this with a subreport
in the main report based on the same query and then linked field seller in
main with field buyer in subreport. Actually quite simple...