Terms aggregation with nested wildcard path

Given the following nested object of nested objects

{
  [...]
  "nested_parent":{
    "nested_child_1":{
      "classifier":"one"
    },
    "nested_child_2":{
      "classifier":"two"
    },
    "nested_child_3":{
      "classifier":"two"
    },
    "nested_child_4":{
      "classifier":"five"
    },
    "nested_child_5":{
      "classifier":"six"
    }
  [...]
}

I'm wanting to aggregate on the wildcard-ish field nested_parent.*.classifier, along the lines of

{
  "size": 0,
  "aggs": {
    "termsAgg": {
      "nested": {
        "path": "nested_parent.*"
      },
      "aggs": {
        "termsAgg": {
          "terms": {
            "size": 1000,
            "field": "nested_parent.*.classifier"
          }
        }
      }
    }
  }
}

which does not seem to work -- possibly because the path and field are not defined clearly enough.

How can I aggregate on nested objects with dynamically created nested mappings which share most of their properties, including the classifier on which I intend to terms-aggregate?