Restricting Webflow CMS pages based on Memberstack

Hi clever people!
I am new to Memberstack but fairly well trained in Webflow. I am developing a student exam portal for a client. There are 5 different levels of exams, and students should only have access to 1 level at a time.

On the home screen there are 5 buttons, 1 for each level. When a button is clicked, it takes you to the specific CMS page for the level, which is an exam page, where you can download the exam.

I have set up the different levels on Memberstack, but I am struggling with the part where you restrict access using the custom attributes as you can only have one custom attribute for all the CMS pages if I am not mistaken.

How can I make only the page for the level that the student is assigned to available to them?
I.e if a student is in level 2 and they click level 3, it will give an error, but if they click level 2 it will take them to the exam page for level 2.

Thanks!