Any idea please? I am still blocked with this problem.

thanks in advance

Sorry for the delay and thanks for bumping this post. The chart itself isn't really capable of doing its own grouping, so it has to be done manually before the data is fed into the chart. Here's one way of doing this.

Create a series for each country and populate the series' datapoints from the other 2 columns.

Here's a code snippet:

private void Page_Load(object sender, EventArgs e)
{
    DataTable dt = new DataTable();
    dt.Columns.Add("country", typeof (string));
    dt.Columns.Add("product", typeof (string));
    dt.Columns.Add("count", typeof (int));
    dt.Rows.Add(new object[] {"France", "Product1", 3});
    dt.Rows.Add(new object[] {"France", "Product2", 6});
    dt.Rows.Add(new object[] {"France", "Product3", 9});

    dt.Rows.Add(new object[] {"Italy", "Product5", 7});
    dt.Rows.Add(new object[] {"Italy", "Product6", 3});
    dt.Rows.Add(new object[] {"Italy", "Product7", 8});

    dt.Rows.Add(new object[] {"Spain", "Product10", 7});
    dt.Rows.Add(new object[] {"Spain", "Product11", 12});
    dt.Rows.Add(new object[] {"Spain", "Product12", 9});

    UltraChart1.ChartType = ChartType.ColumnChart;

    Dictionary<string, NumericSeries> seriesList = new Dictionary<string, NumericSeries>();

    foreach (DataRow row in dt.Rows)
    {
        string countryName = (string) row["country"];
       
        if (!seriesList.ContainsKey(countryName))
        {
            NumericSeries series = new NumericSeries();
            series.Label = countryName;
            series.Points.Add(new NumericDataPoint((int) row["count"], (string) row["product"], false));
            seriesList.Add(countryName, series);
        }
        else
        {
            NumericSeries series = seriesList[countryName];
            series.Points.Add(new NumericDataPoint((int) row["count"], (string) row["product"], false));
        }
    }

    foreach (KeyValuePair<string, NumericSeries> dictionaryEntry in seriesList)
    {
        UltraChart1.Series.Add(dictionaryEntry.Value);
    }
}