Hello Everyone,
I am trying to calculate Average of Average for the below data.

First I want to group the items and calculate the average of values. In the next Iteration, I want to calculate the average of the average what I calculated before. Currently I am able to get the first level average using below aggregation .
"aggs": {
        "item": {
          "terms": {
            "field": "item",
            "size": 0
          } , "aggs": {
            "value": {
              "avg": {
                "field": "value"
              } 
            } 
          } 
        } 
Can someone please help me to calculate the second level average?
Thanks.