title: MongoDB query inside nested objects
body: <p>I am trying to query my document which looks like this </p>
  
  <pre><code>"approvals" : {
      "REV" : "",
      "SS" : "",
      "ABC" : {
          "status" : "Sent for approval",
          "approved_at" : "",
          "approved_by" : "",
      },
      "XYZ" : {
          "status" : "Approved",
          "approved_by" : "xxx@abc.com",
          "approved_at" : ISODate("2020-01-06T09:48:22.777Z"),
      },....
  }
  </code></pre>
  
  <p>The <code>Approval</code> object can have multiple sub documents like ABC,XYZ...etc, I need to query if this "approval" has any sub document whose <code>"status"</code> is not in <code>APPROVED</code> state</p>