In Select2 version 4 each option has the same properties of the objects in the list;
if you have the object
Obj = {
name: "Alberas",
description: "developer",
birthDate: "01/01/1990"
}
then you retrieve the selected data
var data = $('#id-selected-input').select2('data');
console.log(data[0].name);
console.log(data[0].description);
console.log(data[0].birthDate);