Create class item that contain:
Public Class item
{
string Value{get; set;}
string ID{get; set;}
string Flag {get; set;}
}
and give for first group all of them Flag = "a" second class Flag = "b" and so on and when you load you data from data base and when you need to bind the data filter them according to its flag
note: also add column in database called flag to save each item belong to which criteria... best regards