managing javascript this with es6 arrow functions

1.js

someFunction( (arg1, arg2, argN) => {  
  // function body
});

2.js

someFunction( function(arg1, arg2, argN) {  
  // function body
});

3.js

var orgChart = {
  addNewEmployee: function(){
    var employeeDetail = this.getEmployeeDetail();
    
    // => arrow function used here
    employeeDetail.on("complete", (employee) => {
      
      // "this" comes from the surrounding code
      this.selectManager(employee);
    });
    
  },
  
  selectManager: function(employee){
    // do stuff to select the manager
  }
};

4.js

orgChart.addNewEmployee();

5.js

var add = orgChart.addnewEmployee;
add();