Repeating instances help

In a repeating subform I have a DDL with Item A, B and TextFieldA and TextFieldB(Hidden).

In case of item B: TextFieldA become Hidden and TextFieldB become visible.

It's work when I select ItemB 9TextFieldA become Hidden and TextFieldB become visible for the first(default instance).

My problem is when  I click on the button to create a new instances  TextFieldA is visible on all instances

and TextFieldB hidden !

What I have to do in order on all instances:

if ItemA select then: TextFieldA become Visible and TextFieldB become hidden.

if ItemB select then: TextFieldA become Hidden and TextFieldB become visible.

Thanks