How to achieve enum dropdow

How i can select the session1 and session2 in dropdown.. if i am changing 1st value 2nd value get changed if session 1 is selected then session1 and session 2 are option same  if session 2 is selected session session 2 only there in 2nd dropdown how i can achieve this      please give me solution
1 answers

If you use the same attribute from your domain model for both dropdowns, then selecting an option in one dropdown will also change the selected value of the second dropdown.

If you want two dropdowns with the same options to be used independently of each other, you need to have two separate attributes in the domain model that each use the same enumration.