Angular service to share objects between controllers

Lets say I have 2 angular controllers and I want to share data between them, using a service or factory could be used for that and some getters and setters could be used something like this.

app.service('MassShip', function() {
                  var list = [];
                  return {
                        addItem: addItem,
                        getList: getList,
                        getLength: getLength
                  };
                  function addItem(item) {
                        list.push(item);
                  }
                  function getList() {
                        return list;
                  }
                  function getLength() {
                        return list.length;
                  }
      });

However that requires injecting MassShip and whatever other services I create, what I would like to is something like this

app.service('MassShip', function() {
                  
this.TotalOrders = function(){
var list = [];
                  return {
                        addItem: addItem,
                        getList: getList,
                        getLength: getLength
                  };
                  function addItem(item) {
                        list.push(item);
                  }
                  function getList() {
                        return list;
                  }
                  function getLength() {
                        return list.length;
                  }

}

      });

That way I could call MassShip.TotalOrders and I could attach alot of other services to MassShip, however if I do this I get the error

MassShip.TotalOrders.addItem is not a function if I call MassShip.TotalOrders.addItem("hello");

How do I fix this so I could use them in this way