title: TABLEAU - select top 3 based on the values in row
body: <p>Sorry for this possibly easy question but I am a newbie to Tableau.
  Suppose you have a following dataset:</p>
  <pre><code>CLASS,VALUE
      A,3
      A,5
      B,10
      A,9
  </code></pre>
  <p>I want Tableau to have a set/calculated field (which one?) with a formula saying that I want highest 3 values from the dataset <strong>provided they belong to class A.</strong> Is it possible in a formula in Tableau?</p>