Javascript: is categorizing class functions using objects a good design approach?

Let's say I have a component TaskList. It has functions such as addTask, removeTask, editTask, as well as functions like openList and closeList. Let's say I create an object for each category of functions, for example object tasks and object ui, and then I store the functions in their respective objects, like so:

class TaskList {
   constructor(){
       this.tasks = {
           addTask: function(params){
               //Code
           },
           editTask: function(params){
               //Code
           }
           //etc...
       }

       this.ui = {
           closeList: function(){
               //Code
           }
           openList: function(){
               //Code
           }
           //etc...
       }
       //etc...
   }
}

Then you would call each function like so: this.tasks.editTask(...)

Is this a good approach? If no, what are some better alternatives to effectively organizing class functions?