[{"id":"sdfsdfsdf","key":"tryrtyrty","createdAt":"2017-01-28T01:22:14.398Z","counts":[170],"value":"Something"},{"id":"hjmhjhjm","key":"yuiyuiyui","createdAt":"2017-01-28T01:22:14.398Z","counts":[150,160],"value":"Something"}]

db.collection.aggregate([{$set:{"totalCounts":{$sum:"$counts"}}},{$match:{totalCounts:{$gte:200,$lte:400},$expr:{$and:[{$gte:[{"$toDate":"$createdAt"},new Date("2017-01-01T00:00:00.000Z")]},{$lte:[{"$toDate":"$createdAt"},new Date("2017-01-31T00:00:00.000Z")]}]}}},{$unset:["counts","id"]}])