how to truncate the field values in the chart

[#1]

Hi

I have some master tables like company,location,country..

i have one transaction table

i loaded the counry,company,location in list boxes.

i have created one pivot table, i need to truncate that table based on the selection in list boxes

i have field group_tr having values like xxx,yyyy,zzz,aaa

if i select country or location i need to show all the values in the field group_tr

if i select company i need to show the values upto zzz in the field group_tr .

i tried based on getselectedcount but my chart performance was reduced very much.

could anyone help me to resolve this problem...