How to expand a table.

Hello,

I want to produce the following report:

NormalChart

SellerName  ------------ Amount

   +¹Bob                             $10

   +¹Alan                            $50

1 -- The "+" is a button, and when I click on it, the ExpandedChart must appears.

ExpandedChart

SelleName ------------ Region ------------ Amount

   -²Bob                            North                      $5

                                       South                       $3

                                       East                          $2

  +¹Alan                                                          $50

2 -- The "-" is a button and when I click on it the NormalChart must appears.

How can I do that? 

Thanks!