Metadata Pivot

The pivot button looks like a P with an arrow pointing backwards - it can be found in the group of buttons at the right-hand side of the bar at the top of the media browser grid/list view:

Enabling this button allows you to group the media within the currently selected folder(s) according to its metadata and view only the thumbnails which match a specific value.

In the example below, only the clips which were shot with the 70mm lens are selected:

The list of Metadata Keys in the left column of the pivot view will depend on the actual metadata present in the media in the current folder (and its subfolders if the Descend button is enabled)