How to view hidden files when viewing a mac through target disk mode?
Basically, the same way you would view those hidden files on your machine. You just have to go to the correct spot.  Volumes mounted via Target Disk Mode can be found in /Volumes of the filesystem. 

Three common options:


From Terminal.app (found in your Applications folder, under Utilities, you can navigate to the target mode machine starting in "/Volumes". So in Terminal.app do a cd /Volumes to see the target disk and navigate to where you need to go.
From the menu bar of Finder.app, select "Go", then "Go to Folder..." and type in the path you are trying to get to.  e.g. "/Volumes/&lt;target mode HDD&gt;/usr/local/"
Turn on the ability to view hidden files in the Finder. In Terminal.app enter defaults write com.apple.finder AppleShowAllFiles true &amp;&amp; killall Finder and then point &amp; click your way to what you need.