Mongodb：聚合嵌套文档，数组匹配

如何使用MongoDB聚合预测至少有2位作者，最多3位作者的书名

提前谢谢

{
"_id" : 1
"subject":{ 

            "book":[{
                         "bookTitle": "Design and Analysis",
                         "author": ["Levitin"]
                    },
                    {
                         "bookTitle": "Introduction to Algorithms",
                          "author": ["Thomas H Cormen", "Charles E Leiserson", "Ronald L Riverst", "Clifford Stein"]
                    },
                    {
                         "bookTitle": "Introduction",
                         "author": ["James","Adam"]
                    },
}
}

请尝试此查询

db.collection.aggregate([
  {
    "$unwind": "$subject.book"
  },
  {
    "$match": {
      "subject.book.author.1": {
        $exists: true
      },
      "subject.book.author.3": {
        $exists: false
      },
      
    }
  },
  {
    "$project": {
      "subject.book.bookTitle": 1,
    }
  }
])