Select the Control Hierarchy on Top command from the Options menu to cause the Hierarchy for Form dialog to always appear on top of (overlay) your Painter window.
If you do not select this command, the Painter window may be positioned over the Hierarchy for Form dialog when you click on your Painter window.
To cause the Hierarchy for Form dialog to always overlay the Painter window
Select the Control Hierarchy on Top command from the Options menu. (Alternatively, click the Stay on top of Painter icon at the top left of the dialog.)
For details about the Hierarchy for Form dialog, see "Displaying a Hierarchical List of Controls on a Form", earlier in this chapter.