Well i knew about that part, but left it on you.
Here is the complete solution,
//Terms used in the code
name_dropdown= dropdown of the names
operator_dropdown=dropdown of the operators
kv=Key-Value pair Dictionary data structure. Having key=names and value=operators
noValue=default string value when given name is not found
//Code for spliting the operator and binding them in operator_dropdown on selection
of a value in name_dropdown
public void name_dropdown_SelectedIndexChange(object sender, EventArgs e)
String operator_string=kv.TryGetValue(selected_name, out noValue);
All the operators associated with the name in xml would be added in the dropdown.