/usr/share/dbus-1/services/org.gnome.Nautilus.service is in nautilus 1:3.4.1-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | [D-BUS Service]
Name=org.gnome.Nautilus
Exec=/usr/bin/nautilus --no-default-window
|