Visual Studio Lightswitch

Question

Hello,I want to insert a field on a screen of my Lightswitch application which will be check box "true-false" named "published" which is allows me the role of the application administrator to make visible or not to my app the database records that have been modified or imported from another user group.Also will highly appreciate if you can tell me how to define user roles in my  Lightswitch application. 

Thank you!