Help regarding Apify Output schema nested fields

{
  "actorSpecification": 1,
  "name": "my_actor",
  "title": "MY Acror",
  "version": "1.0",
  "buildTag": "latest",
  "environmentVariables": {},
    "storages": {
      "dataset": {
    "actorSpecification": 1,
      "views": {
        "overview": {
          "title": "Overview",
          "transformation": {
        "fields": [
          "listing",
              "details.price_details"
        ],
        "flatten": [
          "listing",
          "details.price_details",
        ]
          },
          "display": {
         "component": "table",
          "properties": {
            "listing": {
              "label": "category",
              "format": "object"
            },
            "details.price_details": {
              "label": "price_details",
              "format": "object"
            }
          }
          }
        }
      }
    }
    }
}