BY default, the FilterBarPromptVisible property is exFilterBarHidden. Use the  FilterBarPromptVisible property to show and use the control's filter-prompt. The filter prompt feature allows you to filter the nodes as you type while the filter bar is visible on the bottom part of the list area. Use the FilterBarPrompt property to specify the HTML caption being displayed in the filter bar when the filter pattern is missing. The FilterBarPromptPattern property specifies the pattern to filter the list. The FilterBarPromptType property specifies how the filter is applied on node names and/or values.

The following screen show shows the filter prompt ( FilterBarPromptVisible property is exFilterBarVisible ):

The following screen show shows the list once the user types "Separator":