Use the "Save" button in the toolbar to save your dashboard. As soon as you've saved your dashboard once, you'll be able to consult it from your list of documents. You can also click on "Save as" to duplicate the dashboard.
Tip: if you quit the tool without saving your dashboard (by closing out of a window or tab, for example), your dashboard will be automatically saved as a draft. If the dashboard has never yet been saved, it will appear as a temporary file in your list of documents. If you have already saved it, simply open the dashboard again to find your last edits. As long as you have not clicked "Save" in the Dashboard Manager, these edits won't be taken into account in the "real" Dashboard.