title: YAML Variables, can you reference variables within variables?
body: <p>I am using a variables.yml file as a template to store different variables, and I was curious if I am able to reference variables within the yml file itself to essentially nest them.</p>
  <p>For example:</p>
  <pre><code>#variables.yml file
  variables:
    food1:        'pineapple'
    food2:        'pizza'
    favoriteFood: '$(food1) $(food2)'
  </code></pre>
  <p>So that when I eventually call upon this variable &quot;favoriteFood&quot;, I can just use ${{ variables.favoriteFood }} and the value should be &quot;pineapple pizza&quot;
  Example:</p>
  <pre><code>#mainPipeline.yml file
  variables: 
  -  template: 'variables.yml'
  steps: 
  -  script: echo My favorite food is ${{ variables.favoriteFood }}.
  </code></pre>
  <p>Am I on the right track here? I can't seem to google to any examples of if this is possible.</p>