Regex to find space

(?:^.+?\K | (?=[0-9]+.+))

Show hidden files and sub directories in root directory

By default the root directory will not show you the directories like /usr, /bin, /etc etc. To make them visible you need to show the hidden files.

Open terminal and type the following command and hit return.

defaults write com.apple.finder AppleShowAllFiles -bool TRUE;killall Finder

Reference: https://themacbeginner.com/view-content-root-directory-mac-os-x/