title: JsonPath: Selecting root level field if satisfies a condition
body: <p>Given the below <strong>Json</strong> input:</p>
  
  <pre><code>{ 
    "category": "fiction",
    "author": "Evelyn Waugh",
    "title": "Sword of Honour",
    "price": 12.99
  }
  </code></pre>
  
  <p>I need to select the author field if the author matches a given name for eg. <code>Evelyn Waugh</code>. I am struggling to write the JsonPath Expression for this. I tried the following with no success. Can anyone suggest the correct expression?</p>
  
  <pre><code>$.author?(@ == 'Evelyn Waugh')
  $.?(@.author == 'Evelyn Waugh')
  $..?(@.author == 'Evelyn Waugh')
  </code></pre>