gistfile1.txt

db.raw_data.aggregate( 
  { $match:{"_id.s":"1234-5678"}},
  { $project : 
    {
      s: "$_id.s",
      res: { d: "$_id.d", v: "$v"},
      dt: 1
    }
  },
  {
    $unwind: "$dt"
  },
  { $group :
    { _id : "$dt",
 	  res: {$addToSet: "$res"}
    }
  },
  { $project : 
    {
      _id : 0,
      type: "$_id",
      res: 1,
    }
  }
);