Gnome 3 developers decided that they are too cool to give the users an option to add "Open parent" into Navigation menu of Nautilus 3.X. So right now we have Back, Forward and Search buttons only. If someone wants to go Up, he has either to Click GO then Open Parent or use Alt+Up hotkey. I suggest to get "Open parent" to Nautilus menu back in Mint as it was in Nautilus 2 and make happy users who prefer classic address bar, not folder view. Thank you.