db={bookUser:[{"authored_by":"asdfs","general":{"address":{"city":"XYZ"}}},{"authored_by":"jkfo21","general":{"address":{"city":"YYZ"}}}],center_data:[{"authored_by":"asdfs","books":{"name":"alpha"},"book_type":"adventure","general":{"address":{"city":"ABC"}}},{"authored_by":"jkfo21","books":{"name":"sigma"},"book_type":"drama","general":{}}]}

db.bookUser.aggregate([{$lookup:{from:"center_data",localField:"authored_by",foreignField:"authored_by",as:"books"}},{$project:{authored_by:1,general:1,books:{$filter:{input:"$books",as:"book",cond:{$and:[{$eq:["$$book.book_type","adventure"]}]}}}}}])