Statistics grouped by multiple filters, grouped by filter

GET twitter/_search
{
  "size": 0,
  "aggs": {
    "by_cities": {
      "filters": {
        "filters": {
          "beijing": {
            "match": {
              "city": "北京"
            }
          },
          "shanghai": {
            "match": {
              "city": "上海"
            }
          }
        }
      }
    }
  }
}