title: MongoDB return a result as of [object Object]
body: <p>I have a multi layers schema:</p>
  
  <pre><code>{
    a:String,
    aList: 
    [
       {
          b:String,
          bList:
          [
              {
                  c:String,
                  cList 
                  [
                     d1:String
                     d2:String   
                  ]
              }  
          ] 
       }
    ]
  } 
  </code></pre>
  
  <p>The problem is that when I retrieve as followedin</p>
  
  <pre><code>A.find( {a:aid, "aList.b":bid}, {_id:0, "aList.$.bList" : 1})
  </code></pre>
  
  <p>The bList is always returned as a list of Strings and I can't get the original data</p>
  
  <pre><code>{
    aList:
    [
       {
          bList: [ "[object Object]", "[object Object]", "[object Object]"] 
       }
    ]
  } 
  </code></pre>