联表查询后怎么处理字段

A表中有_id字段，B表中有一个rec_id字段，关联了A表的_id，联表查询后 查出来的结果是

    "_id": {  
            "_value": "660b6b338620667bb46aeb4a",  
            "record-deduction": [{  
                "_id": "660ba4c199c6244dcfcc6edf",  
                "record_book_id": "660b6b338620667bb46aeb4a",  
                "staffList": [{  
                    "name": "局长",  
                    "price": "50"  
                }, {  
                    "name": "哒哒",  
                    "price": "50"  
                }],  
                "delStatus": 0,  
                "create_date": 1712039025313  
            }]  
        },

怎么把list单独列出来而不是嵌套在_id里面。