Ah, I see now. Yes, you can add a property change event to the top field to check for when the text changes, and then you can use grabFocus() to move focus to the 2nd field.
E.g.
If event.propertyName == 'text':
event.source.parent.getComponent('textfield2').grabFocus()
Make sure your text fields have defer updates options checked
(see available methods/properties from the javadoc for PMITextField for where grabFocus() came from)