Hi,
In case of the MS Chart control, if using the Stacked bar / Stacked column types, you can group different series into separate groups by setting the StackedGroupName custom attribute
// Set the first two series to be grouped into Group1
Chart1.Series["LightBlue"]["StackedGroupName"] = "Group1";
Chart1.Series["Gold"]["StackedGroupName"] = "Group1";
If you download the MS Chart samples (http://code.msdn.microsoft.com/mschart/Release/ProjectReleases.aspx?ReleaseId=4418), you can see something very similar to what you are looking for in
/WebSamples/ChartTypes/BarColumnCharts/Stacked/StackedChart.aspx - Grouping option.
Hope this helps!