I have the same problem. The file I want from my time machine backup is ~/Library/ApplicationSupport/Google Earth/myplaces.kml.
NOTE: I start by first locating the new null .kml file then go to time machine. Have to use the GO menu with option key down then click on Library.
First problem: Can't get to the backup prior to restore UNLESS I change to user folder or hard drive BUT THEN 2nd problem: Library subfolder is hidden and can't get to it.
Something to do with system hiding the Library folder, I think.
WHAT IS THE SOLUTION??? ANYBODY. Solving this would help in restoring pre-restore data bases for lots of other applications I have to reinstall.
This mess all started because "mail" would not work with Yosemite. Had to install a clean new system thereby losing all MY non apple applications.
Being this is a reply to a 2012 message I don't expect much from this reply.
Chuck