You are trying to use the EL to return a value expression to be used as a method expression in a single expression. The JEE7 tutorial states:
9.3 Value and Method Expressions The EL defines two kinds of expressions: value expressions and method expressions. Value expressions can either yield a value or set a value. Method expressions reference methods that can be invoked and can return a value.
You can achive this behaviour using javascript or use a library that offers you a dynamic menu component, like primefaces.