db={author:[{_id:ObjectId("63c242130b17d5516e0cb499"),author_name:"Vyom",book_ids:["63c242330b17d5516e0cb49a","63c242410b17d5516e0cb49b"]}],book:[{_id:"63c242330b17d5516e0cb49a",author_id:"63c242130b17d5516e0cb499",book_name:"True Love",genere:"horror"},{_id:"63c242410b17d5516e0cb49b",author_id:"63c242130b17d5516e0cb499",book_name:"Monster Strike",genere:"romance"},]}

db.author.aggregate([{$match:{_id:ObjectId("63c242130b17d5516e0cb499")}},{$lookup:{from:"book",localField:"book_ids",foreignField:"_id",as:"book_info",pipeline:[{$project:{_id:1,book_name:1}}]}}])