title: Azure cosmos DB 3.6 Mongo doesn't support Compound index that has embedded field
body: <p>When I run the following command in Cosmos DB 3.6, </p>
  
  <p><code>db.collectionName.ensureIndex({"Contract.ContractNumber":1, "PBPNumber":1})</code></p>
  
  <p><code>Contract.ContractNumber</code> is the sub-document path.</p>
  
  <p>I got his error</p>
  
  <pre><code>{
     "ok" : 0,
     "errmsg" : "Compound index does not currently support nested documents or arrays.",
     "code" : 115,
     "codeName" : "CommandNotSupported"
  }
  </code></pre>
  
  <p>The same command succeeds in out of box Mongo.</p>
  
  <p>Is there anyway to do it?</p>
  
  <p>Thanks</p>