Groups and sub groups

Dear members,
I have designed a report using crystal report , say of fields quantity,itemname,total in which i have groups done by country and then customer name and sales employee name.
Now i need to collapse/expand the groups according to click of user. say if user clicks the country button it should show the sub totals of quantity and total and then its details.
in next level, if the customer/user clicks at customer name it should display the sub totals of qty and total and then its details.

Please help me in this regard,

Thanks and regards,
Venkatesh.R