Aggregation

curl -X GET "http://localhost:9200/my-index-000001/_search?pretty" -H 'Content-Type: application/json' -d "${JSON}"

{
  "aggs": {
    "mycount": {
      "terms": {
        "size": 50,
        "field": "account.type",
        "include": ["common", "admin"]
      }
    }
  }
}

Even when you have array of objects, the syntax is the same as if there were no arrays.

Sometimes you may need to check the Field mapping to see some hidden fields. For example, user.name may be a text and therefore cannot be aggregated, but user.name.keyword may be of type keyword and can be aggregated.