How to group and rowFilter a column

my datagridview get it records from a database and looks like this:

[Country]     
  Gh
  Ng
  Sa
  Gm
  Sw
  Ru

I wanna now Filter this column using a combobox. I' ve two values in my combobox Africa and Europe. My expectation is to get something like this:

//If i select Africa in the combobox
  Gh
  Ng
  Sa
// And if i select Europe
  Gm
  Sw
  Ru

That's my code so far:

private void combobox1_SelectedIndexChanged(object sender, EventArgs e)
    {

            try
            {
                //Check an see what's in the dgv
          DataView dv = new DataView(dt);
          dv.RowFilter = "[Country]  LIKE '%" + combobox1.Text.Trim() + "%'";
          datagridview1.DataSource = dv;
            }
            catch (Exception)
            {
    MessageBox.Show("Column not found", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

        }

How can i group them and implement it?