Check if this is a button or a submitButton. If its a submitButton, you need to setForwardURL to the page to which you want to navigate to. Please check the Javadoc for OA FRamework and it should be easy. If you are explicitly looking for code snippet, I can write up something.
In which ever pages you are calling this page, extend controller of those pages and in PFR of that controller give the following code
String s4 = pageContext.getCurrentUrlForRedirect();
then in your second page you can call this session variable by
use this session value for page redirect.