{
  "title": "Some title",
  "comments": [
    {
      "comment": "Comment 1",
      "role": "NEWBIE"
      "date":    "2014-10-18"
    },
    {
      "name":    "Comment 2",
      "role": "VETERAN"
      "date":    "2014-10-12"
    }
  ]
}

queryset = queryset.filter('match', **{'comments.role': 'NEWBIE'})

queryset = queryset.sort('comments.date')