如何把副表下数组字段元素下的指定属性提取出来参与排序？

有如下查询结果：关系是每一个单词都很多练习记录，练习记录里有一个练习时间，希望能用最近后一次练习记录的时间来排序。自己试了很多写法都没有能完成，请求高手们能指点一下。

我自己写了一个方法，但是得到的record_info始终是一个数组，我是希望得到recorder_info中第一条数据的last_practice_date

let wordTemp =  db.collection('iword_word').where("level_id=='6541c1cf9755e3e35f1ba674' && size(chinese)>0").field('_id,level_id,word,en_symbol,us_symbol,en_sound,us_sound,pic,chinese,english,sample').getTemp();  

let levelTemp = db.collection('iword_level').field('_id, name as text').getTemp();  

let recordTemp = db.collection("iword_record").field('_id as record_id, user_id, word_id, is_right,times,last_practice_date').orderBy(  
'last_practice_date desc').limit(3).getTemp();  

db.collection(wordTemp,levelTemp, recordTemp).field("_id.iword_record.last_practice_date as record_info").orderBy('record_info desc').get()

数据格式如下：
[
{
"_id": {
"_value": "654273fd7f79070231c044d0",
"iword_record": [
{
"_id": "6543654a9755e3e35f5f2b6a",
"is_right": true,
"last_practice_date": 1699915057700,
"record_id": "6543654a9755e3e35f5f2b6a",
"times": 3,
"user_id": "6541c3e5fe975fe6ff692764",
"word_id": "654273fd7f79070231c044d0"
},
{
"_id": "654457a3f082104ad5823709",
"is_right": true,
"last_practice_date": 1698915057700,
"record_id": "654457a3f082104ad5823709",
"times": 8,
"user_id": "6541c3e5fe975fe6ff692764",
"word_id": "654273fd7f79070231c044d0"
},
{
"_id": "654457b8466d4107c4e16933",
"is_right": true,
"last_practice_date": 1698913057700,
"record_id": "654457b8466d4107c4e16933",
"times": 1,
"user_id": "6541c3e5fe975fe6ff692764",
"word_id": "654273fd7f79070231c044d0"
}
]
},
"record_info": [
1699915057700,
1698915057700,
1698913057700
]
},
{
"_id": {
"_value": "654273fd7f79070231c044ba",
"iword_record": [
{
"_id": "65439234189f86f5bedd5107",
"is_right": true,
"last_practice_date": 1698927156260,
"record_id": "65439234189f86f5bedd5107",
"user_id": "6541c3e5fe975fe6ff692764",
"word_id": "654273fd7f79070231c044ba"
}
]
},
"record_info": [
1698927156260
]
},
{
"_id": {
"_value": "654273fd7f79070231c044bb",
"iword_record": [
{
"_id": "65439234189f86f5bedd5108",
"is_right": false,
"last_practice_date": 1698927156260,
"record_id": "65439234189f86f5bedd5108",
"user_id": "6541c3e5fe975fe6ff692764",
"word_id": "654273fd7f79070231c044bb"
}
]
},
"record_info": [
1698927156260
]
}
]