As mentioned in Ubuntu Wiki, there are two type of quicklists: static and dynamic. Bookmarks quicklist is a dynamic quicklist. So, it will be available only if your
nautilus is running.
nautilus is always running in background unless you or some process killed it.
If you disabled
nautilus to manage your desktop (for example you hid desktop icons) to restore quicklists you can:
- Open a folder. From now on nautilus will be running even if you close all Nautilus windows, so quicklists will be displayed.
- Just add
nautilus -n to a start-up script like
.xsessionrc in your home folder (see this answer). Or go to Startup Applications, click "Add" and insert the command
nautilus -n. This way you can have nautilus autostarting in the
background even if hide-desktop-icons feature is in use.