Database
[{state:"California",date:"2010-08-11",otherData:"Something Else"},{state:"Arizona",date:"2020-09-10",otherData:"Something Else2"},{state:"Arizona",date:"2020-08-10",otherData:"Something Else9"},{state:"Arizona",date:"2010-08-10",otherData:"Something Else1"},{state:"California",date:"2011-08-11",otherData:"Something Else3"},{state:"California",date:"2010-12-01",otherData:"Something Else4"},{state:"Arizona",date:"2020-08-11",otherData:"Something Else0"},{state:"NewYork",date:"2020-08-11",otherData:"Something Else3"}]
Query
db.collection.aggregate([{$group:{_id:"$state",doc:{$max:{date:"$date",state:"$state",otherData:"$otherData"}}}},{$replaceRoot:{newRoot:"$doc"}}])