Is it really true that Nautilus 3.x hasn't the »open parent« button any more? Today I tried the second beta of Ubuntu 11.10 and I am deeply frustrated. Since Gnome3 and this whole Unity thing it feels a bit of always having to be afraid, that a new release will remove some of the main functions you are using in all days work. Back to the point: Is there a chance to get it back?
The Gnome Dev's think that the Gnome 2 interface overcomplicates matters. That's perhaps a judgement call.
Perhaps the new short-cut key Alt + Up Arrow is something you can use.
Nautilus 3 automatically opens all folders in a tree - so you can click on any parent - they call this "breadcrumbs"
There is also a little arrow to open-up sub-folders below the parent:
The answer given so far is that we have to use the "bread crumbs" but I strongly prefer the always-use-location-entry to be true. We can also use the difficult key combo of alt-uparrow, but it's easier to just highlight and delete the last folder in the location bar.
However, I just discovered the best way by playing around: the Backspace key.
At first I thought Backspace was going to the previous folder, but then realized the next folder button wouldn't work after Backspace and eventually realized it was just what we're looking for because Backspace goes to the parent folder. Backspace is the fast way to delete the last folder listed in the location bar (as long as you don't have a cursor already in the location bar).
If the cursor is in the location bar, you just have to select a file to get the cursor out of the location bar and then hit Backspace to get to the parent.