Hidden files are always shown if you have chosen "Show hidden files, folders and drives" in Folder Options. Hidden files are never shown if you choose "Don't show hidden files, folders and drives" in Folder Options. You find Folder Options by clicking the (start menu) and tyoing "Folder Options" in search field. Choose then "View" and then one of the above mentioned options.
Option 1 - To Hide a Specific File from Recent in Quick access:
1. Open File Explorer, and click/tap on Quick access in the navigation pane.
2. In Quick access, select one or more files under Recent files.
3. Right click or press and hold on the selected file(s), and click/tap on Remove from Quick access.
Option 2 - To Hide a Specific Folder from Frequent in Quick access:
1. Open File Explorer, and click/tap on Quick access in the navigation pane.
2. In Quick access, select one or more unpinned folders under Frequent folders.
3. Right click or press and hold on the selected folder(s), and click/tap on Remove from Quick access.
Option 3 - To Stop Hiding Files and Folders from Quick access:
1. Clear File Explorer history. - Check here:
http://www.tenforums.com/tutorials/3476-recent-items-frequent-places-reset-clear.html#option3
Clearing File Explorer history deletes the info Windows saved about the files and folders you use as well as what you've typed in the address bar. If you clear your history, the Recent files section will disappear from Quick access until you open a file, and all Frequent folders will disappear from Quick access except those you pinned until you open a folder.