Hi, sigtaupres.

You should put away  OutlookGroupBy option:

grid.DisplayLayout.ViewStyleBand = Infragistics.Win.UltraWinGrid.ViewStyleBand.OutlookGroupBy;

And use  your own logic for grouping columns via creating a class and implement IGroupByEvaluator interface. This interface allows you to determine which rows belong in the same group and which don't. Then assign it to a column:

GroupEvaluator eval = new GroupEvaluator();
grid.DisplayLayout.Bands[0].Columns["MyColumn"].GroupByEvaluator = eval;

In the next methods of GroupByEvaluator you can define your custom logic:

   public object GetGroupByValue(UltraGridGroupByRow groupByRow, UltraGridRow row)
        {
            return null; // place your own logic
        }

        public bool DoesGroupContainRow(UltraGridGroupByRow groupByRow, UltraGridRow row)
        {
            return false; //place your own logic
        }

Note that the ICustomGroupByEvaluator will only get called to evaluate rows that are adjacent. So you may also need to implement a SortComparer on the column to make sure the column is sorted in the correct order before it is grouped.

Alex.