The default behavior of subpanels is to close when the user chooses a control, unless the user has moved the subpanel from its original position.
The Front Panel can be configured to keep subpanels open until the user explicitly closes them.
Create a new Front Panel configuration file in:
System-wide: /etc/dt/appconfig/types/language/*.fp
Personal: HomeDirectory/.dt/types/*.fp
Copy the default PANEL definition from /usr/dt/appconfig/types/language/dtwm.fp to the new file:
PANEL FrontPanel { … }
Add the following field to the PANEL definition:
SUBPANEL_UNPOST False
Save the new configuration file.
Choose Restart Workspace Manager from the Workspace menu.