title: field within the object of array in Mongodb
body: <p>The sample structure is as follows:</p>
  
  <pre><code>{
      "_id": 1,
      "College_name" : "abcdef"
      "Students": [
  {
    "name": "a",
    "Grade": "First"
  },
  {
    "name": "b",
    "Grade": "Second"
  },
  {
    "name": "c",
    "Grade": "First"
  },
  {
    "name": "d",
    "Grade": "First"
  
  }
  ]
  }
  </code></pre>
  
  <p>What I am not getting is - I want to get all <strong>("Grade" : "First")</strong> objects in the array and insert only ("Grade" : "First") objects to other collection where <strong>("College_name" : "abcdef")</strong>. What is the optimal solution for this? 
  Is this possible through aggregation??
  Please help me out to solve this.</p>