Please check out the original documentation for most up-to-date information.
Looker offers the ability to copy a LookML dashboard into a folder as a user-defined dashboard. A user-defined dashboard is edited through the user interface instead of through LookML. The ability to edit the new user-defined dashboard depends on the user’s access settings for the folder that contains the dashboard.
You can bulk import LookML dashboards into folders as user-defined dashboards, or you can import a single LookML dashboard from the LookML dashboard folder or while viewing the LookML dashboard.
The Converting from LookML to user-defined dashboards documentation page details the followings: