mongoTemplate查询嵌套文档分页怎么写？

Question

集合中数据是这样的：
{

"_id" : ObjectId("5acc90cd66178815e8f6647b"),
"parent_id" : "5ac97f4a63e8db17cc20f799",
"standard_number" : "DZJW 2103.7—2017",
"standard_chinese" : "电子检务工程 检察业务数据元  第7部分：控告检查",
"standard_english" : "The electronic engineering data element in procuratorial work Part 7：Prosecuting prosecution",
"preface" : "测试前言",
"scope" : "本部分xxxx与共享。",
"normative_quote_file" : "下列xxxx告检察",
"term_definition" : "GB/T 19488.1-2004界定的术语和定义适用于本文件。",
"catalogs" : [
    {
        "catalog_name" : "4.1　信访受理审查案件",
        "subcatalogs" : [
            {
                "subcatalogs_name" : "4.1.1  受理情况",
                "subcatalog" : [
                    {
                        "chinese_name" : "信访类别",
                        "internal_identifier" : "DE02.07.001",
                        "version" : "v1.0",
                        "definition" : "信访人提供信访案件的类别。",
                        "data_type" : "字符型",
                        "data_format" : "a..30",
                        "range" : "DZJW 2203.7-2017中CC02.07.001。",
                        "synonymous_nouns" : "",
                        "measuring_unit" : "",
                        "remarks" : ""
                    },
                    {
                        "chinese_name" : "信访类别代码",
                        "internal_identifier" : "DE02.07.002",
                        "version" : "v1.0",
                        "definition" : "信访人提供信访案件类别的代码。",
                        "data_type" : "字符型",
                        "data_format" : "n1",
                        "range" : "DZJW 2203.7-2017中CC02.07.001。",
                        "synonymous_nouns" : "",
                        "measuring_unit" : "",
                        "remarks" : ""
                    },
                    {
                        "...":"..."
                    }
                ]
            },
            {
                "subcatalogs_name" : "4.1.2  XXXX",
                "subcatalog" :[
                    {
                        "...":"..."
                    }
                ]
            }
        ]
    },
    {
        "catalog_name" : "4.2　举报类信访案件",
        "subcatalogs" : [
            {
                "chinese_name" : "奖励日期",
                "internal_identifier" : "DE02.07.094",
                "version" : "v1.0",
                "definition" : "举报线索经查证属实，提起公诉后被法院做出有罪生效判决的，本院给予举报人一定物质奖励的具体时间。",
                "data_type" : "日期型",
                "data_format" : "YYYYMMDD",
                "range" : "",
                "synonymous_nouns" : "",
                "measuring_unit" : "",
                "remarks" : "DZJW 2102.4-2017中DE01.04.01。"
            },
            {
                "...":"..."
            }
        ]
    }
],
"current_version" : "20180410-v1.01",

}
因为有的目录是还有子目录，有的没有子目录。当我想查这条记录中catalogs的前20个带chinese_name的具体信息数据，mongotemplate中该怎么写查询方法？