Elasticsearch 查询嵌套字段，嵌套对象列表中限制只有匹配的才返回结果，怎么写 dsl

存储的数据是

      {
          "id" : "xxxxx",
          "model" : "aaacc",
          "product" : "xxxxasdf",
          "idc" : "ccaa",
          "backup" : [
            {
              "id" : 123,
              "type" : "ssh-11",
              "part" : "ssh-12",
            },
            {
              "id" : 456,
              "type" : "ssh-22",
              "part" : "ssh-23",
            }
          ]
        }

返回匹配 backup.type:ssh-11 的结果，正常返回会把 backup 列表都带出来。但是希望之返回比例的子项

希望返回

	{
          "id" : "xxxxx",
          "model" : "aaacc",
          "product" : "xxxxasdf",
          "idc" : "ccaa",
          "backup" : [
            {
              "id" : 123,
              "type" : "ssh-11",
              "part" : "ssh-12",
            }
          ]
        }