Reference Editor Layouts
The Reference Editor has three layouts, which are accessible from the Reference Editor toolbar. The layouts are File List, File List/Outliner, and File List/Outliner/Viewport.
A Text Filter field appears in the File List and Outliner views in the Reference Editor. To filter the items that are displayed in each of these views, type text into the field.
The icon to the left of the Text Filter field indicates if the Text Filter is currently active. If the Text Filter is active, click the icon to turn the filter off.
For more information about using the Text Filter field, see Control which objects or attribute types appear in an editor.