Thanks for your reply! But i am sorry, you completely missed the point. I know what a file manager is.
"Then i understood that it is not Nautilus, but Gtk File chooser.
Now i wonder if there is a way to use "native" Thunar and not this GTK file chooser?"
The question was if there is a way to make browsers use default file manager and not the GTK file chooser?
Or at least where are the GTK file chooser configs to make changes to it?
Point 3 - Sad news. Taking Point 1 and Point 2 into consideration, you are stuck with applications using whatever the Desktop Environment's look and feel for opening and closing flies. This is what the Desktop Environment is designed to do. To provide a consistent look and feel across all applications.