You can filter the main contents display to show only items matching chosen criteria.
Note that all filters will apply to the contents of the selected library folder (and sub-folders if Recurse is enabled).
Display all items.
Display the library item that corresponds to the segment under the active play-head.
Display the library items that correspond to the marked segments.
Display the library items that are not in use in the composition or marked region.
Comp / Clip / Proxy
Display compositions / clips / proxies.