title: Can we use of Nested where clause in sails js Collection
body: <p>I am trying below queries to get the output which has start_date greater than current date.</p>
  
  <p>These in structure of my collection:</p>
  
  <pre><code>{ 
      "_id" : ObjectId("5aeac6cd1b7e6f252832ca0e"), 
      "recruiter_id" : null, 
      "university_id" : null, 
      "type" : "quiz", 
      "name" : "Enter scheduled quiz without end date", 
      "description" : "Even after detailed market research, some products just don't work in the market. Here's a case study from the Coca-Cola range. ", 
      "quizpoll_image" : "story_7.jpeg", 
      "status" : "1", 
      "quizpoll_type" : "scheduled", 
      "duration" : {
          "duration_type" : "Question wise", 
          "total_duration" : "1000"
      }, 
      "questions" : [
          {
              "question_id" : "5aeaa4021b7e6f00dc80c5c6"
          }, 
          {
              "question_id" : "5aeaa59d1b7e6f00dc80c5d2"
          }
      ], 
      "date_type" : {
          "start_date" : ISODate("2018-05-01T00:00:00.000+0000")
      }, 
      "created_at" : ISODate("2018-05-01T00:00:00.000+0000"), 
      "updated_at" : ISODate("2018-04-26T07:58:17.795+0000")
  }
  </code></pre>
  
  <p>This the query I am trying :</p>
  
  <pre><code>var isoCurrentDate = current_date.toISOString();
          var quizScheduledData = await QuizListingCollection.find({
                  where: ({
                      'type':'quiz',
                      'status':'1',
                      'quizpoll_type':'scheduled',
                      'date_type' :{
                              'start_date':{
                                  '&gt;': isoCurrentDate       
                              }
                          }
                      })
              });
  </code></pre>
  
  <p>This is the error I get when I hit this api in postman</p>
  
  <pre><code>{
      "cause": {
          "name": "UsageError",
          "code": "E_INVALID_CRITERIA",
          "details": "Could not use the provided `where` clause.  Could not filter by `date_type`: Unrecognized modifier (`start_date`) within provided constraint for `date_type`."
      },
      "isOperational": true,
      "code": "E_INVALID_CRITERIA",
      "details": "Could not use the provided `where` clause.  Could not filter by `date_type`: Unrecognized modifier (`start_date`) within provided constraint for `date_type`."
  }
  </code></pre>