[{"command1":"A","command2":"B","parseCount":0},{"command1":"A","command2":"B","parseCount":1},{"command1":"A","command2":"B","parseCount":2},{"command1":"C","command2":"D","parseCount":1},{"command1":"E","command2":"F","parseCount":2},]

db.collection.aggregate([{"$sort":{"parseCount":-1}},{"$group":{"_id":{"command1":"$command1","command2":"$command2"},"object":{"$first":"$$ROOT"}}},{"$project":{"_id":"$object._id","command1":"$object.command1","command2":"$object.command2","parseCount":"$object.parseCount"}}])