db.Order.aggregate([
    { '$match'    : { "company_id" : ObjectId("54c0...") } },
    { '$sort'     : { 'order_number' : -1 } },
    { '$facet'    : {
        metadata: [ { $count: "total" }, { $addFields: { page: NumberInt(3) } } ],
        data: [ { $skip: 20 }, { $limit: 10 } ] // add projection here wish you re-shape the docs
    } }
] )