example.json

curl -XGET "http://localhost:9200/_search" -d'
{
  "query": {
    "bool": {
      "should": [
        {
          "match": {
            "parent.text": "query string"
          }
        },
        {
          "has_child": {
            "score_mode": "avg",
            "type": "child",
            "query": {
              "match": {
                "child.text": "query string"
              }
            }
          }
        }
      ]
    }
  }
}'