wpf listcollectionview grouping by multiple columns and calculating the amount and quantity

public void group_multi_column_and_calculate_amount_and_quantity()
{
    var c = new ListCollectionView(Items)
    {
        GroupDescriptions =
        {
            new PropertyGroupDescription("Name"),
            new PropertyGroupDescription("Date")
        }
    };
    c.GroupDescriptions.Add(new PropertyGroupDescription("Name"));
    c.GroupDescriptions.Add(new PropertyGroupDescription("Date"));
    c.GroupDescriptions.Add(new PropertyGroupDescription("Product"));
    c.GroupDescriptions.Add(new PropertyGroupDescription("Quantity"));
    c.GroupDescriptions.Add(new PropertyGroupDescription("Amount"));
    dataGrid.ItemsSource = c;
}