initially i tried that but mongo throws an error , if i use $ it takes first matched element .
{ MongoError: cannot use the part (body of body.viewed.main) to traverse the element ({body: [ { type: "in", message: "yes", _id: ObjectId('587e2be40456010a3f4e3b8a'), createDate: new Date(1484663780842), hidden: false, viewed: { sub: false, main: false } }, { type: "in", message: "yes", _id: ObjectId('587e2be40456010a3f4e3c8a'), createDate: new Date(1484663780842), hidden: false, viewed: { sub: false, main: false } } ]})