[{"time":1,"submitted":true},{"time":2,"submitted":true},{"time":3,"submitted":true},{"time":4,"submitted":false},{"time":5,"submitted":false},{"time":6,"submitted":false}]

db.collection.aggregate([{$set:{timeSort:{$multiply:["$time",{$cond:["$submitted",-1,1]}]}}},{$sort:{submitted:1,timeSort:1}},{/** comment this out to remove the field* $unset: "timeSort"*/}])