I have a folder that starts with a dot
. but unable to display them in Finder.
How can I say that for folder X Finder should also display hidden files/folders?
I don't think you can set this for individual folders. To set it globally, so that Finder always shows hidden files, run Terminal and enter the following two commands:
defaults write com.apple.finder AppleShowAllFiles TRUE killall Finder
To switch back, do the same but substitute FALSE for TRUE.
You can customize Finder through Terminal commands such that it defaults to show/hide hidden files.
To show hidden files and restart Finder:
defaults write com.apple.finder AppleShowAllFiles YES; killall Finder /System/Library/CoreServices/Finder.app
To hide hidden files and restart Finder:
defaults write com.apple.finder AppleShowAllFiles NO; killall Finder /System/Library/CoreServices/Finder.app