Database
[{ContractNumer:10,SomeField:"ABC",ValueContract:17.7,DataProcessing:"2021-01-19 10:23:20:10",Status:1},{ContractNumer:10,SomeField:"ABC",ValueContract:17.7,DataProcessing:"2022-01-19 10:23:20:10",Status:1}]
Query
db.collection.aggregate([{$group:{"_id":"$ContractNumer","max":{"$max":"$DataProcessing"}}}])