If set RowGroup.displayMode as RowGroupDisplayMode.MERGED, you can display the cells contained in the same group except Basic Row Grouping in one merged cell.
chkMerged_click: function (ev) {
var newMode = ev.target.checked ? DataLudi.RowGroupDisplayMode.MERGED : DataLudi.RowGroupDisplayMode.BANDED;
grid.rowGroup().setDisplayMode(newMode);
}
You can specify the way to display the header or footer of each group differently depending on the expanded or hidden state through RowGroup.expandedAdornments and collapsedAdornments properties.
Export to an Excel file.