Hi!!!
I have to do a report that show the information in this way:

                                                       Total Sales
Sales Clase Major $sum(sales_item per Sales Clase Major)
     Sales Clases Minor $sum(Sales_item per Sales clase minor)
           Item $sum(Sales per Item)
To do this I create three group. One that show total per Major Clase, other that show total per Minor Clases, and the las onw total per item.

What I want to do is first show only the total per Sales Clase Major,


Sales Clase Major Total Sales
 Fruits $1230.87
 Meat $1349.09

Then if they push Fruits show all the minor clases of Fruits

Sales Clase Major Total Sales
 Fruits $1230.87
     Tropical $ 710.47
      Season $ 520.40
 Meat $1349.09
And the same to the item, if they push Tropical show all the tropical fruits.

How can I do this?

Thanks a lot for you time.

Create formulas to set up your groups, and then group on your formulas. If you then format the report by hiding the lower groups, you can use drill-down functionality to display the details.