title: Select TOP 2 values for each group
body: <p>I'm having problem with getting only TOP 2 values for each group (groups are in column).</p>
  
  <p>Example :</p>
  
  <pre><code>ID    Group    Value
  1        A       30
  2        A      150
  3        A       40
  4        A       70
  5        B        0
  6        B      100
  7        B       90
  </code></pre>
  
  <p>I expect my output to be </p>
  
  <pre><code>ID    Group    Value
   1       A       150
   2       A        70
   3       B       100
   4       B        90
  </code></pre>
  
  <p>Simply, for each group I want just 2 rows with the highest Value</p>