Database
[{"_id":ObjectId("5988814feb46972540cebccd"),"bookStore":[{"books":[{"book":{"bookId":7501}},{"book":{"bookId":7502}},{"book":{"bookId":7500}}]}]}]
Query
db.collection.aggregate([{$addFields:{bookStore:{$map:{input:"$bookStore",as:"bs",in:{books:{$filter:{input:"$$bs.books",as:"b",cond:{$eq:["$$b.book.bookId",7501]}}}}}}}}])