search option not working in nested gridview, differen table

Question

In the nested gridview there are multiple rows for each in the main gridview. Related both with same id . Here id as billno  select LbillHead.BillNo,LDate,custid,custname,Addrtype,(selectsum(Qty) from LbillDetails where LbillHead.BillNo=LbillDetails.BillNo) as Qty,   (selectsum(Total) from LbillDetails where LbillHead.BillNo=LbillDetails.BillNo) as Total,(selectsum(GSTAmt) from LbillDetails where LbillHead.BillNo=LbillDetails.BillNo) as GSTAmt,  (selectsum(InvAmt) from LbillDetails where LbillHead.BillNo=LbillDetails.BillNo) as InvAmt,LbillDetails.description  "from LbillHead  innerjoin custinfo on custinfo.custid=LbillHead.nameinnerjoin lbilldetails on lbilldetails.descid=LbillHead.billno   where LbillHead.BillNo <> 0 " + str + "orderby LbillHead.BillNo desc