Hi Naren,
No need to split Billing Operator object. Create a variable-
V_IL_NL= If Match([Billing Operator];"*IL")=1 Then "IL" ElseIf Match([Billing Operator];"*NL")=1 Then "NL"
1) Put V_IL_NL variable below Billing Operator object header.
2) Sort and create break on this variable.
3) Delete Footer column. it will automatically create when you apply break.
4) Hide V_IL_NL variable from this header.
~Anuj