How to return hour by hour average for the last X days?

[Yi_HAN]

I have the following script to return an aggregation hour by hour of last x days on ExecNom:

GET /mkt-with-time/_search
{
  "size": 0,
  "query": {
    "range": {
      "@timestamp": {
        "gte": "now-7d/d",
        "lte": "now-2d/d"
      }
   }
  },
  "aggs": {
		"per_hour": {
			"date_histogram": {
				"field": "@timestamp",
				"calendar_interval": "hour"
			},
			"aggs": {
				"avg_execnom": {
					"avg": {
						"field": "ExecNom"
					}
				}
			}
		}
	}
}

this returns:

"aggregations": {
    "per_hour": {
      "buckets": [
        {
          "key_as_string": "2022-08-14T00:00:00.000Z",
          "key": 1660435200000,
          "doc_count": 3633,
          "avg_execnom": {
            "value": 252701.0352904938
          }
        },
        {
          "key_as_string": "2022-08-14T01:00:00.000Z",
          "key": 1660438800000,
          "doc_count": 3651,
          "avg_execnom": {
            "value": 258698.55131756698
          }
        },
		...
		{
          "key_as_string": "2022-08-15T00:00:00.000Z",
          "key": 1660521600000,
          "doc_count": 3559,
          "avg_execnom": {
            "value": 248551.24137114585
          }
        },
        {
          "key_as_string": "2022-08-15T01:00:00.000Z",
          "key": 1660525200000,
          "doc_count": 3553,
          "avg_execnom": {
            "value": 250348.02511778387
          }
        },
        {
          "key_as_string": "2022-08-15T02:00:00.000Z",
          "key": 1660528800000,
          "doc_count": 3692,
          "avg_execnom": {
            "value": 258052.43654516252
          }
        },
		...
		]
	}
}

I have data hour by hour for today:
for the simplicity, I write 'today' as if it is today's date.

{
  "key_as_string": "todayT02:00:00.000Z",
  "key": 1660528800000,
  "doc_count": 3692,
  "avg_execnom": {
	"value": 258052.43654516252
  }
},

{
  "key_as_string": "todayT03:00:00.000Z",
  "key": 1660528800000,
  "doc_count": 3692,
  "avg_execnom": {
	"value": 258052.43654516252
  }
}
...

I am looking for a way to compare hour by hour, today's data versus the one of last X days.
I have already today's data, how to find the hour by hour average for last X days.

To be explicit:

[
	avg(2022-08-14T00:00:00, 2022-08-15T00:00:00, ..., 2022-08-22T00:00:00),
	avg(2022-08-14T01:00:00, 2022-08-15T01:00:00, ..., 2022-08-22T01:00:00),
	avg(2022-08-14T02:00:00, 2022-08-15T02:00:00, ..., 2022-08-22T02:00:00),
	...
	avg(2022-08-14T23:00:00, 2022-08-15T23:00:00, ..., 2022-08-22T23:00:00)
]

Inspired from this: Average per day of week aggregation - #2 by abdon

this is my last try but does not work:

GET /mkt-with-time/_search
{
  "size": 0,
  "aggs": {
    "orders_per_hour_of_day": {
      "terms": {
        "script" : {
            "lang": "painless",
            "source": "doc['@timestamp'].value.getHour()"
        },
        "size": 24
      },
      "aggs": {
        "dayOfWeek": {
          "terms": {
            "script": {
              "lang": "painless",
              "source": "doc['@timestamp'].value.getDayOfWeekEnum()"
            }
          },
          "aggs": {
            "total_execnom": {
              "sum": {
                "field": "ExecNom"
              }
            },
            "number_of_weeks": {
              "date_histogram": {
                "field": "@timestamp",
                "calendar_interval": "week"
              }
            },
            "average_execnom_per_hour_day_of_week": {
              "bucket_selector": {
                "buckets_path": {
                  "totalExecNom" : "total_execnom",
                  "number_of_weeks": "number_of_weeks._bucket_count"
                },
                "script": "params.totalExecNom / params.number_of_weeks"
              }
            }
          }
        }
      }
    }
  }
}

Do you have an idea how to achieve that?

Thanks!