Show Everything is a convenient way to quickly see all files in the folder without actually clearing any filters that may be in place. It’s local to the folder tab it is used in.
Don't confuse Show Everything mode with the search tool Everything by voidtools, which Opus also supports.
You can activate Show Everything mode by clicking the count of hidden items on the status bar.
You can also turn it on using the Show Everything in the Folder dropdown menu. The filter bar has a Show Everything checkbox which also lets you toggle the mode on and off.
The default status bar displays Everything if Show Everything mode is active.
Click the Everything label to turn it off (or use the other methods mentioned above).
Show Everything disables all types of filtering within the current folder tab, with one exception: It does not affect folders hidden while in Flat View Mixed (No Folders) mode.