You can use the send(actionName, arguments)
method.
App.IndexController = Ember.ArrayController.extend({
actions: {
actionFoo: function() {
alert('foo');
this.send('actionBar');
},
actionBar: function() {
alert('bar');
}
}
});
Here is a jsfiddle with this sample http://jsfiddle.net/marciojunior/pxz4y/