The Filter Bar is such a handy tool that I keep it open all the time. The clickable toggles for folders and files are particularly useful in my opinion. How about adding similar toggles for Hidden and System files?
I know that buttons for Hidden and System are available in the Folder dropdown of the default Menu toolbar but it would be so much easier to toggle this way and nice to have a breakdown of how many are Hidden vs how many are System, as shown in this mock up.
Regards, AB
hide it,press * ,is show
When the filter bar is shown permanently I don't have to touch the keyboard to toggle folders/files. I often want to toggle folders temporarily.
Regards, AB
+1
+1. Taking it a step further, it would be great if we could add other standard filters such as "greater than size X," "modified within last X," and "by tag" to name a few. Of course, having the ability to customize the filter bar would be cool too... 
You can add those to normal menus & tooobars already.
Leo, I'm guessing this is directed at me. I get it and have it that way now, but like the idea of having standard filters on a dedicated filter bar. I'm sure there are design/code implications, not to mention a potential lack of demand, that may make this a pipe dream. It doesn't hurt to ask though!
It sounds like you're trying to turn the filter bar into a full-blown toolbar, and Opus already has those 
Nah, just a full-blown FILTER bar... with filter tools! 
Like the Find panel?