Dashboard Elements Storing in CMS

Hi, I am currently creating a dashboard that is using a collection item to store user data. What I want to do is create elements that the user selects and then this stores there selection in a CMS field.

An example would be: The user logs into their dashboard, selects a specific book, that book then show’s in their CMS field for books and when they view the book in their dashboard is shows as selected.

Hope this makes sense and look forward to hearing from you guys.