On clicking a button, how can we bring up another form or interface?

Question

I am looking for sample implementation on how to bring up an already existing interface or a form (which is a collection of interfaces) in the interface view itself. I see some questions around redirecting to process model but in this case, I am only concerned about opening in the interface for the user. 
 
 Thanks

Ramesh · Answer

Please follow the steps below to show a interface from another without submitting the form. 
 1. Create interface I1 with sub-interface I2(show/hide based on flag) and ButtonWidget B(submit = false()). 
 2. Create a local variable to show/hide I2. 
 3. Have logic to update local variable when clicked on B. That should show I2 whenever B is clicked.