Elasticsearch count on nested objects

#delete index
curl -XDELETE 'http://localhost:9200/blog'

#Create index with mapping
curl -XPUT 'http://localhost:9200/blog' -d '
{
  "mappings": {
    "post": {
      "properties": {
          "title": {
            "type": "string"
          },
          "body": {
            "type": "string"
          },
          "nested_comments": {
            "type": "nested",
            "properties": {
              "comment": {
                "type": "string"
              },
              "date": {
                "type": "date"
              },
              "name": {
                "type": "string"
              },
              "stars": {
                "type": "long"
              }
            }
          },
          "unnested_comments": {
            "type": "object",
            "properties": {
              "comment": {
                "type": "string"
              },
              "date": {
                "type": "date"
              },
              "name": {
                "type": "string"
              },
              "stars": {
                "type": "long"
              }
            }
          },
          "tags": {
            "type": "string"
          },
          "title": {
            "type": "string"
          }
        }
    }
  }
}'

#index a few posts
curl -XPUT 'http://localhost:9200/blog/post/1' -d '{
  "title": "Nest eggs",
  "body":  "Making your money work...",
  "nested_comments": [ 
    {
      "name":    "John Smith",
      "comment": "Great article",
      "age":     28,
      "date":    "2014-09-01"
    },
    {
      "name":    "Alice White",
      "comment": "More like this please",
      "age":     31,
      "date":    "2014-10-22"
    }],
  "unnested_comments": [ 
    {
      "name":    "John Smith",
      "comment": "Great article",
      "age":     28,
      "date":    "2014-09-01"
    },
    {
      "name":    "Alice White",
      "comment": "More like this please",
      "age":     31,
      "date":    "2014-10-22"
    }
  ]
}'

curl -XPUT 'http://localhost:9200/blog/post/2' -d '{
  "title": "Bad news",
  "body":  "Markets have been really bad - stay away from the stock market...",
  "nested_comments": [ 
    {
      "name":    "Michael Smith",
      "comment": "Silly article",
      "age":     32,
      "date":    "2015-01-01"
    },
    {
      "name":    "Jack Reany",
      "comment": "Should we sell then?",
      "age":     14,
      "date":    "2015-01-02"
    },
    {
      "name":    "Mark Hamilton",
      "comment": "Do you have proof for this?",
      "age":     76,
      "date":    "2015-01-02"
    }

  ],
  "unnested_comments": [ 
    {
      "name":    "Michael Smith",
      "comment": "Silly article",
      "age":     32,
      "date":    "2015-01-01"
    },
    {
      "name":    "Jack Reany",
      "comment": "Should we sell then?",
      "age":     14,
      "date":    "2015-01-02"
    },
    {
      "name":    "Mark Hamilton",
      "comment": "Do you have proof for this?",
      "age":     76,
      "date":    "2015-01-02"
    }

  ]
}'

#trying to automatically get count for fields in unnested object
curl -XGET 'http://localhost:9200/blog/post/_search' -d '
{
 "filter": {
   "script": {
     "script": "doc['unnested_comments.id'].values.size() == 2"
    }
  }
}
'

#trying to automatically get count for fields in nested object
curl -XGET 'http://localhost:9200/blog/post/_search' -d '
{
 "filter": {
   "script": {
     "script": "doc['nested_comments.name'].values.size() == 2"
    }
  }
}
'