Allow post_filter access to the _score value

I found it's allowed to access _score inside the aggs, but not allowed to access this field in the post_filter queries, though it's executed after the aggs. Is there a reason for that it's not accessible or it could be added in the Elasticsearch in the future versions?

An example query:

  "body": {
    "post_filter": {
      "script": {
        "script": "_score > 100 && _score < 200"
    "query": {
      "function_score": {
        "functions": [{
          "script_score": {
            "script": "doc['price'].value * 100"
  "index": ["items"],
  "type": []

script_score could be much more complex, it's just an example.

Please comment also here on the github issue:

Related problem to this issue: