title: Mongodb Query: Query by nested value with unknown parent
body: <p>The records in my database are structured like:</p>
  
  <pre><code>{"_id": "1", children: {"bOb": {age: 5}, "SallY": {age: 10}}}
  {"_id": "2", children: {"JeFF": {age: 8}, "BilL": {age: 4}}}
  </code></pre>
  
  <p>I am looking for a query that will allow me to find a document that contains an age for a particular child. For an example, if I pass "4" as a parameter, I expect the following result:</p>
  
  <pre><code>{"_id": "2", children: {"JeFF": {age: 8}, "BilL": {age: 4}}}
  </code></pre>
  
  <p>Unfortunately, it is out of the scope of my project to restructure the entire schema that was dumped upon me. I appreciate any insight</p>