This option is not supported in version 2.1.  Currently, the first parameter listed alphabetically will appear on the Overview Display.

The Overview display shows one Parameter representative of the Block.  For example, the Absolute Deviation Parameter of a PID Block is usually shown on the Overview to indicate near normal (a small value) or abnormal (a large value).  In version 2.1, the default Overview display is text only; it could easily be replaced with a graphical display or bar type display.

Overview in Parameter Properties will in a future release define whether this Parameter will appear in the Overview Display.  The Overview Display is a standard system display that provides a summary of all the Faceplate Groups including Blocks.