using new group and following expression solved my problem.
sum(if(wildmatch(Type,'Expense'),Amount * -1,Amount))
and if you don't want show Expense amount in negative then go to Number tab select Integer/Fixed to
and set below pattern
Grouping seems ok in a simple example, but normally you have much more different blocks in a P&L where you have to sum up the Totals. Pls. see the modified xls from above, as an example, and the colored 'blocks'.
Then you may need 3-4 or more columns for grouping, and it will be very confusing in a Pivot chart.
So how to cope with that, or am I misunderstanding something? (I work on a PandL right now.... 🙂 )