title: Is it possible to sort nested documents in ElasticSearch?
body: <p>Lets say I have the following mapping:</p>
  
  <pre><code>"site": {
    "properties": {
      "title":       { "type": "string" },
      "description": { "type": "string" },
      "category":    { "type": "string" },
      "tags":        { "type": "array" },
      "point":       { "type": "geo_point" }
      "localities":  { 
        type: 'nested',
        properties: {
          "title":       { "type": "string" },
          "description": { "type": "string" },
          "point":       { "type": "geo_point" }
        }
      }
    }
  }
  </code></pre>
  
  <p>I'm then doing an "_geo_distance" sort on the parent document and am able to sort the documents on "site.point". However I would also like the nested localities to be sorted by "_geo_distance", inside the parent document.</p>
  
  <p>Is this possible? If so, how?</p>