title: Get only one item with specific field value
body: <p>How to distinct result by specific field value. For example i have <code>group_id</code> field and i don't want to get multiple results with same group_id.</p>
  
  <pre><code>[{"name": "Eva", "group_id": "female"}, 
   {"name": "Marina", "group_id": "female"},
   {"name": "Raf", "group_id": "male"},
   {"name": "Manvel", "group_id": "male"}]
  </code></pre>
  
  <p>For example this is my documents list. From this list i need to get only one male and one female. So i think i need to group by field "group" and get only one from match that group. I think this is something simple, and i don't need to write that match. In docs probably example is for more complex cases.</p>
  
  <p><a href="https://i.stack.imgur.com/ldZ4z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ldZ4z.png" alt="enter image description here"></a></p>