[{"name":"George","applicationId":1,version:1},{"name":"George","applicationId":1,version:2},{"name":"George","applicationId":1,version:3}]

db.collection.aggregate([{$group:{_id:{"name":"$name","applicationId":"$applicationId"},not_latest:{"$push":"$version"}}},{$project:{_id:1,not_latest:{$slice:["$not_latest",0,{$subtract:[{$size:"$not_latest"},1]}]}}}])