Unfortunately, Gnome's nautilus address bar is not showing the full path in its top bar. How can I change this behavior?
I'm looking for a solution to display a editable text field instead, like in the good old days.

Press Ctl and while holding it down, press L.
To return to the original breadcrumb view, make sure that the editable text area has the focus then press the Esc key.
To make it permanent (i.e. to always use location entry) run:
gsettings set org.gnome.nautilus.preferences always-use-location-entry true
or
dconf write /org/gnome/nautilus/preferences/always-use-location-entry true
Same commands to revert to breadcrumbs (just replace true with false).