This property affects WinChart and not WebChart. The drill back button is not available in WebChart.
When active, a drill back button is automatically displayed at the top-left corner of the chart grid (it may appear outside of Pie and Doughnut charts since they have no upper-right corner). It appears behind graphed objects when those objects are highlighted. It isn't possible to relocate this button, and it is not shown by default.
As an alternative to using ShowButton, developers can provide their own Button or user interface experience to control drill back. The UltraChart class exposes a DrillBack() method that can be called by application logic (such as in an ClickEvent handler).
Whether the user navigates up the drill down hierarchy using the provided button or an application generated DrillBack() call, the effect of returning to the parent chart is the same. Since this button does not appear, it is incumbent upon developers to either turn on ShowButton or provide their own DrillBack() call to enable users to revisit parent charts.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2