您可以在嵌套聚合的filter aggregation内部使用nested aggregations：）。

PUT test_days
{
  "mappings": {
    "properties": {
      "workingdays": {
        "type": "nested",
        "properties": {
          "mon": {
            "type": "nested",
            "properties": {
              "availability": {
                "type": "boolean"
              },
              "title": {
                "type": "text",
                "fields": {
                  "keyword": {
                    "type": "keyword"
                  }
                }
              },
              "notes": {
                "type": "text"
              }
            }
          },
          "tue": {
            "type": "nested",
            "properties": {
              "availability": {
                "type": "boolean"
              },
              "title": {
                "type": "text",
                "fields": {
                  "keyword": {
                    "type": "keyword"
                  }
                }
              },
              "notes": {
                "type": "text"
              }
            }
          }
        }
      }
    }
  }
}

POST test_days/_doc?refresh
{
  "workingdays": {
    "mon": {
      "availability": true,
      "title": "Monday",
      "notes": ""
    },
    "tue": {
      "title": "Tuesday",
      "notes": "On Tuesdays, drop off and pick up times must be scheduled between 12pm to 2pm",
      "availability": false
    }
  }
}

GET test_days/_search
{
  "size": 0,
  "aggs": {
    "total": {
      "nested": {
        "path": "workingdays"
      },
      "aggs": {
        "monday": {
          "filters": {
            "filters": {
              "monday_availability": {
                "nested": {
                  "path": "workingdays.mon",
                  "query": {
                    "term": {
                      "workingdays.mon.availability": {
                        "value": true
                      }
                    }
                  }
                }
              },
              "tuesday_availability": {
                "nested": {
                  "path": "workingdays.tue",
                  "query": {
                    "term": {
                      "workingdays.tue.availability": {
                        "value": true
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

注意：区分大小写！！请仔细检查是否使用workingDays或workingdays。