Define performers with nested Conditions

I tried to define performers to a task with a easy nested condition. My organisation defines different skills and differernt areas. The skills and areas are assiged to the users. The condition i like to establish is quit easy. (skills = "A" or skills = "B") and areas = "XXX" How can i define this. All of my attemps doesnt work correctly. Regards Thomas Version 10.7.0.2126