ElasticSearch - Get only matching nested objects with All Top level fields in search response

Question

let say I have following Document:

{
    id: 1,
    name: "xyz",
    users: [
        {
            name: 'abc',
            surname: 'def'
        },
        {
            name: 'xyz',
            surname: 'wef'
        },
        {
            name: 'defg',
            surname: 'pqr'
        }
    ]
}

I want to Get only matching nested objects with All Top level fields in search response. I mean If I search/filter for users with name 'abc', I want below response

{
    id: 1,
    name: "xyz",
    users: [
        {
            name: 'abc',
            surname: 'def'
        }
    ]
}

How can I do that?

Reference : select matching objects from array in elasticsearch

Answer 1

If you're ok with having all root fields except the nested one and then only the matching inner hits in the nested field, then we can re-use the previous answer like this by specifying a slightly more involved source filtering parameter:

{
  "_source": {
    "includes": [ "*" ],
    "excludes": [ "users" ]
  },
  "query": {
    "nested": {
      "path": "users",
      "inner_hits": {        <---- this is where the magic happens
        "_source": [
          "name", "surname"
        ]
      },
      "query": {
        "bool": {
          "must": [
            {
              "term": {
                "users.name": "abc"
              }
            }
          ]
        }
      }
    }
  }
}