How is it possible to create a pivot table in rtf template with group above ?

Hi,
sorry, but i pass my time more on the net to look for information than to create reports
we have reports very complicated and it's bi publisher seems less powerfull than oracle reports for simple things
like horizontal sections for instance.
But my new problem is to add a pivot table with group above
i create a groupe section
after i insert a pivot table with the tool
but in each group section i have the same pivot table
but when i put a normal table it's OK  WHY ?

and i haven't found exemple

regards

Marc