How to coax Bridge > Filter > File Type to return results from subfolders?

Using Bridge 15.0.4.534, although this was also the case in the previous version, before i updated just now.

WHAT I'M SEEING

I have a folder containing many nested folders, most of which contain image files.
In the sidebar, i have the top level folder selected, and below that, i have expanded FILE TYPE.

The list of filtering checkboxes under File Type show just the contents of the currently selected folder.

GOAL

Have the Filter > File Type feature return results from all sub-folders

Not sure if the above would constitute less of a filter and more of a search.  But i was assuming there'd be some way in Bridge to show me everything of X file type within the current folder PLUS sub-folders.