How do I change the location of Gnome Shell notifications?
Installing the extension Panel OSD. Open the URL in Firefox and enable the extension.
Open the Tweak Tool
and configure your settings
After removing the extension, you have to restart your GNOME Shell via
Alt-F2, type r
and Enter
In Gnome shell 3.16, location of notification has been moved to the top. By default it is not possible to change the location of notifications in the Gnome shell, and best to my knowledge there is no extension to accomplish this task, but i could be wrong about that.