How can I add all records from a previous form into a multi-select field on a new form?

How can I add all records from a previous form into a multi-select field on a new form?

I'm building a simple app to manage a tutoring company (eventually all but payroll). I have Form A, where the user can add a new Content Area (such as Mathematics, Natural Sciences, etc.). I also have Form B, where the user can add a new Tutor. There is a "Qualifications" section on Form B where I want to have a Multi-Select (or a Checkbox) field where the user may select multiple Content Areas that the tutor is qualified to tutor. For this reason, I need all records from Form A to populate the choices in a Multi-Select (or a Checkbox) field when Form B loads. I suppose this is similar to a dynamic drop-down menu when the user selects a state, the next drop-down menu populates with a list of cities within said state. Any help?