That is a Navigation Bar on your screenshot.
As far as I'm aware: in order to see that bar floating it has to be hidden in GUI. For that: make sure that View | Navigation Bar
is inactive/un-checked.
With the above condition in place, the shortcut for Navigate | Jump to Navigation Bar
(Alt + Home on Windows using Default keymap) will bring that bar floating. Otherwise (with Navigation Bar permanently visible) that action/shortcut should just focus existing Navigation Bar.