Aggregation not working on query results

[Sangeeth_Kumar]

I have query like

{
  "size": 1,
  "query": {
    "bool": {
      "must": [
        {
          "bool": {
            "must": [
              {
                "simple_query_string": {
                  "query": "sangeeth",
                  "default_operator": "OR"
                }
              }
            ]
          }
        },
        {
          "bool": {
            "should": [
              {
                "match": {
                  "CreatedBy._id": "Us_78eb6dd0a46a11e8a1b10242ac12000b"
                }
              },
              {
                "match": {
                  "_created_by._id": "Us_78eb6dd0a46a11e8a1b10242ac12000b"
                }
              },
              {
                "match": {
                  "CurrentAssignedTo._id": "Us_78eb6dd0a46a11e8a1b10242ac12000b"
                }
              }
            ],
            "minimum_should_match": 1
          }
        }
      ]
    }
  },
  "aggregations": {
    "count_per_flows": {
      "terms": {
        "field": "_type"
      },
      "aggregations": {
        "Name": {
          "terms": {
            "field": "Flow.Name.keyword"
          }
        },
        "Id": {
          "terms": {
            "field": "Flow._id.keyword"
          }
        }
      }
    }
  }
}

I have mentioned size as 0 in my query. I got exact one document as result. But aggregation returns result with match of all documents.