Database
[{businessID:"B1",userID:"U1",userBusinessID:1,data:"hello1"},{businessID:"B1",userID:"U1",userBusinessID:2,data:"hello2"},{businessID:"B2",userID:"U1",userBusinessID:1,data:"hello4"},{businessID:"B1",userID:"U2",userBusinessID:1,data:"hello5"},]
Query
db.collection.aggregate([{$match:{userID:"U1"}},{$sort:{userBusinessID:-1}},{$group:{_id:{businessID:"$businessID",userID:"$userID"},data:{$first:"$$ROOT"}}},{$replaceRoot:{newRoot:"$data"}}])