Database
[{NonUniqueId:1,Name:"book",Price:10.54},{NonUniqueId:1,Name:"book",Price:12.54},{NonUniqueId:1,Name:"book",Price:13.54},{NonUniqueId:2,Name:"book",Price:11.54},{NonUniqueId:2,Name:"book",Price:12.54},{NonUniqueId:2,Name:"book",Price:13.54}]
Query
db.collection.aggregate([{$match:{Name:"book"}},{$sort:{Price:1}},{$group:{_id:"$NonUniqueId",product:{$first:"$$ROOT"}}},{$replaceWith:"$product"}])