{
...
   "aggregations": {
      "locations": {
         "buckets": [
            {
               "key": "poland",
               "doc_count": 15,
               "sex": {
                  "buckets": [
                     {
                        "key": "female",
                        "doc_count": 3,
                        "buckets": [
                          {
                              "to": 20,
                              "doc_count": 1,
                              "avg_salary": {
                                  "value": 2000
                              }
                          },
                          {
                              "from": 20,
                              "to": 40,
                              "doc_count": 1,
                              "avg_salary": {
                                  "value": 4000
                              }
                          },
                          {
                              "from": 40,
                              "doc_count": 1,
                              "avg_salary": {
                                  "value": 4500
                              }
                          }
                        ]
                     },
                     {
                        "key": "male",
                        "doc_count": 12,
                        "buckets": [
                          {
                              "to": 20,
                              "doc_count": 3,
                              "avg_salary": {
                                    "value": 2500
                              }
                          },
                          {
                              "from": 20,
                              "to": 40,
                              "doc_count": 8,
                              "avg_salary": {
                                  "value": 6000
                              }
                          },
                          {
                              "from": 40,
                              "doc_count": 1,
                              "avg_salary": {
                                  "value": 4500
                              }
                          }
                        ]
                     }
                  ]
               }
            },

...
}