title: Zsh tab-completion for "cd .."
body: <p>How can I configure the Zsh tab-completion such that when I type <code>cd ..&lt;TAB&gt;</code> it expands to <code>cd ../</code> and after pressing <code>&lt;TAB&gt;</code> again proposes the folders in the parent directory for completion?</p>
  
  <p>E.g. it should show the same behavior as when typing for example <code>cd Documents&lt;TAB&gt;</code> which expands to <code>cd Documents/</code> and after pressing <code>&lt;TAB&gt;</code> again proposes the folders in <code>Documents</code> for completion.</p>
  
  <p>As a starting point for configuration I use an empty <code>.zshrc</code> and Zsh 4.3.9 from MacPorts.</p>