can I restore a dashboard?
One answer

See instructions at the bottom of this article.
https://jazz.net/wiki/bin/view/Main/DashboardRevisionHistory
https://jazz.net/wiki/bin/view/Main/DashboardRevisionHistory
Comments

This seems to only be available for project dashboards. If I work with private dashboards and delete one, there seems to be no way. Am I correct?

That's interesting. I just did a test and found that it was not working at all with personal dashboard. Probably the Wiki page needs to be modified accordingly. Specifically the last bit of the page
This will display the revision history for that deleted dashboard in the same way as with other dashboards. You can then find the latest revision before the deletion and copy & paste the content to a new personal dashboard.The first half is true and I do get a feed showing the revision history, but the second half is false as every single link in the feed results in "not found".
P.S. I tested with CLM 5.0.2. Not sure whether it did work in older versions.