How to sort the composite aggregation results by score?

[betty]

Elasticsearch ver: 6.2.4

I have now got the results of composite aggregation by:

GET index/_search
{
  "aggs": {
    "my_buckets": {
      "composite": {
        "sources": [
          {
            "name": {
              "terms": {
                "field": "name.keyword"
                }
            }
          }
        ]
      }
    }
  },
  "query":{

   }
}

To simplify the question, the query part is omitted here.

I can get the results like:

"aggregations": {
    "my_buckets": {
      "buckets": [
        {
          "key": {
            "name": "Bill Gates"
          },
          "doc_count": 1
        },
        {
          "key": {
            "name": "Steven Paul Jobs"
          },
          "doc_count": 1
        },
        {
          "key": {
            "name": "Gates Godar"
          },
          "doc_count": 1
        }
        ]
       }
      }

I noticed that the order of the search results is not sorted by the score. If I use the following DSL:

{
  "_source": "name",
  "query":{

   }
}

The results are ordered by score. That's what I want. But I need to use aggregations to group several attributes in the index and get the value.

How can we achieve to sort the composite aggregation results by the score? Is there a way to combine the "aggregations" with the "_source" part? It confuses me for several days, any idea is appreciated!

Thanks.