This just started happening today. I have a folder on my internal drive (same symptoms with all folders, so it doesn't matter which one). The folder has sub-folders and files (any type of files, so the filetype doesn't matter, but let's use .mp3 files as an example). I type a space in the search window and select to search "folder name", rather than "This Mac". The search results show only the first folder's contents, including the sub-folders in the main folder. The results do not show any files that are in any sub-folders. I've tried various combinations of search terms and criteria, created new folders, restarted Finder, etc. I haven't tried creating a new account (I will, as a last resort, if needed). Is there some setting I'm forgetting that enables searching sub-folders? Any other ideas?