I recently restored from my iCloud drive and it was a little messy. It worked out ok but the process can be made easier. Here is what I did with a fresh install of DEVONthink after reinstalling macOS High Sierra:
Enabled iCloud Sync - I had to know what name I had used to create my archive. Fortunately I knew what I had named it.
Right clicked the database I needed first and selected the option to import it. Two things happened at this point: the directory ~/Databases was created and the database was restored to /Applications.
Problem Statement: The ~/Databases directory is the correct location to restore databases to while /Applications is obviously not.
Comments: I did not specify ~/Databases but it was somehow created. The information must have been stored somewhere and retrieved. However a look at my iCloud drive would have revealed that my archive was labeled “Archives” rather than asking me.
Feature Request: When syncing databases to remote storage devices record two pieces of information: location of the database on the local system, and the name/location of the archive on the remote system. When restoring from sync offer to either “Restore to original location” or “Restore to a different location.” The backup program on my Linux box does this and it’s a great feature.