data.cs

MergeBlockInfo mergeBlockInfo = new MergeBlockInfo("Products");

mergeBlockInfo.BlockMergingCondition = 
  new List<TXTextControl.DocumentServer.DataShaping.FilterInstruction>()
{
    new TXTextControl.DocumentServer.DataShaping.FilterInstruction(
        "RenderProducts",
        TXTextControl.DocumentServer.DataShaping.RelationalOperator.Equals,
        true
        )
};

mergeBlockInfo.ColumnNames = 
  ribbonReportingTab1.DataSourceManager.PossibleMergeFieldColumns.Select(
    column => column.ColumnName).ToList();

MergeBlockSettings settings = new MergeBlockSettings(BlockTemplateType.PlainParagraph);

ribbonReportingTab1.DataSourceManager.InsertMergeBlock(textControl1, mergeBlockInfo, settings);