{
  b : 1,
  d : [{
      e: 3,
      f: {
          type : "Point",
          coordinates:[-2, 53]
      }
    }
  ]
}

{
  "b" : 1,
  "d.e" : 1,
  "d.f": "2dsphere"
}

db.indextest.drop();

var row = {
  b : 1,
  d : [{
      e: 3,
      f: {
          type : "Point",
          coordinates:[-2, 53]
      }
    }
  ]
};

db.indextest.createIndex({
  "b" : 1,
  "d.e" : 1,
  "d.f": "2dsphere"
},{
    "2dsphereIndexVersion": 2
});

db.indextest.save(row);

var query = {
  b : 1,
  d : {
    $elemMatch : {
      e : 3,
      f:{
         $geoWithin : {
           $centerSphere : [[-2, 53], 2.523219554550177E-4]
         }
       }
    }
  }
};

var explain = db.indextest.find(query).explain();
var count = db.indextest.find(query).count();

printjson(explain);
printjson( { "count" : count } )