You could write a recursive loop to walk down all the levels of grouping in the grid, but there is a much easier way.

The Rows collection has a number of methods that will make it much easier for you to get the rows you want.

In this case, you can do this:

        For Each row As UltraWinGrid.UltraGridRow In ugBackOrders.Rows.GetFilteredInNonGroupByRows()
            If row.Cells("Tick").Value = True Then
                'Do Something
            End If
        Next

The code above will get all the data rows on any level of the grid, excluding any rows that are filtered out.

If you want filtered rows, too, you could just do this:

        For Each row As UltraWinGrid.UltraGridRow In ugBackOrders.Rows.GetAllNonGroupByRows()
            If row.Cells("Tick").Value = True Then
                'Do Something
            End If
        Next

When you group by a column, the Rows collection only contains the UltraGridGroupByRows. UltraGridGroupByRow exposes a Rows collection, which contains each of the rows in that group.