Access buttons/movie clips from extending class?

1

I have a flash project (.fla file) that includes an external actionscript package. Inside the package I am trying to reference buttons and movie clips that are in the main timeline, but it keeps throwing reference errors. Here is what the package looks like:

package {
    import flash.display.*;
    import flash.utils.*;
    import flash.events.*;

    public class dfyEditor extends Sprite {         
        function dfyEditor() {}
        
        function setupActions() {
            btnSave.addEventListener('click', function(){
                btnSaveClip.gotoAndStop(3)
            });
        }
    }
}

Inside the main flash file, I have this code to instantiate it:

var dfy:dfyEditor = new dfyEditor();
dfyEditor.setupToolbar();

What is the right way to reference those items from within the class? Thank you!!