Post_filter on nested type raises elastic error

Question

My index mapping: https://pastebin.com/eBPKXufH

The query:

{
  "query": {
    "bool": {
      "filter": [
        [
          {
            "nested": {
              "path": "categories",
              "query": {
                "match": {
                  "categories.cats": "360"
                }
              }
            }
          }
        ]
      ]
    }
  },
  "sort": {
    "sale": {
      "order": "desc"
    }
  },
  "post_filter": [
    {
      "nested": {
        "path": "64",
        "filter": {
          "match": {
            "64.value": "207"
          }
        }
      }
    }
  ]
}

The error I get is:

{
  "error": {
    "root_cause": [
      {
        "type": "x_content_parse_exception",
        "reason": "[1:29] [bool] failed to parse field [filter]"
      }
    ],
    "type": "x_content_parse_exception",
    "reason": "[1:29] [bool] failed to parse field [filter]",
    "caused_by": {
      "type": "illegal_state_exception",
      "reason": "expected value but got [START_ARRAY]"
    }
  },
  "status": 400
} 

What I try to accomplish is filter by nested value of categories.cats which is constant query and then post_filter it by nested value of object 64 etc, which is filter criteria but I also need all other values in aggregations (did not post the aggregation query, since it is not relevant I think)

Answer 1

You have too many square brackets:

"bool": {
  "filter": [
    [                  <--- remove this and the closing one
      {

should be

"bool": {
  "filter": [
      {