Hi Vanessa,

I've attached some code demonstrating how you can do this using business
objects.  You should be able to do it with relational tables as well, but I'm
not so familiar using tables as datasource.  The code assumes you have a
DataGridView, ComboBox and TextBox on your Form

   public partial class Form1 : Form
   {
       public Form1()
       {
           InitializeComponent();

           ClassA a = new ClassA("A");
           BindingSource sourceA = new BindingSource(a, "");
           BindingSource sourceB = new BindingSource(sourceA, "BList");
           BindingSource sourceC = new BindingSource(sourceB, "CList");
           dataGridView1.DataSource = sourceB;
           comboBox1.DataSource = sourceC;
           comboBox1.DisplayMember = "Name";
           textBox1.DataBindings.Add("Text", sourceC, "Id");
       }
   }

   public class ClassA
   {
       private string _name;

       public string Name
       {
           get { return _name; }
           set { _name = value; }
       }

       private BindingList<ClassB> _bList;

       public BindingList<ClassB> BList
       {
           get { return _bList; }
           set { _bList = value; }
       }
       public ClassA(string name)
       {
           Name = name;
           BList = new BindingList<ClassB>();

           BList.Add(new ClassB(Name + " B 1"));
           BList.Add(new ClassB(Name + " B 2"));
       }
   }

   public class ClassB
   {
       private string _name;

       public string Name
       {
           get { return _name; }
           set { _name = value; }
       }

       private BindingList<ClassC> _cList;

       public BindingList<ClassC> CList
       {
           get { return _cList; }
           set { _cList = value; }
       }
       public ClassB(string name)
       {
           Name = name;
           CList = new BindingList<ClassC>();

           CList.Add(new ClassC(Name + " C 1"));
           CList.Add(new ClassC(Name + " C 2"));
       }
   }

   public class ClassC
   {
       static int count = 0;
       private string _name;

       public string Name
       {
           get { return _name; }
           set { _name = value; }
       }

       private int _id;

       public int Id
       {
           get { return _id; }
           set { _id = value; }
       }
       public ClassC(string name)
       {
           Name = name;
           Id = count++;
       }
   }