VLSub for Mac
After installing VLSub, simple go to the VLC menu > Extensions and click on the VLSub extension. From VLSub's main window, you can download subtitles by name or by hash and in numerous languages.
To install VLSub, copy the 'vlsub.lua' file to:
/Applications/VLC.app/Contents/MacOS/share/lua/extensions/ (for all users)
/Users/your_name/Library/Application Support/org.videolan.vlc/lua/extensions/ (for the current user)
Note: If the 'extensions' folder does not exist, create one yourself.