Why wouldn't you show the data view with the Course and display the list over an association?
Yes, Marc is correct. To add more to @Marc's answer, please find the details below;
In the domain model, add one to many association that is one course is associated to many students. Now in the microflow where you create new student object make sure you associate every new student with course (see image below). Then call page B from microflow and pass course object. On page B, add a data view and set data source as Context and entity as Course. Within that data view, add a list view or data grid to show all the students associated with the selected course.
You can read further about association in Mendix
Hope this helps!
If the list you are showing is generated based on user interaction on page A, there must be an association set between your coures and student entities and/or there must be some attributes on the student that identifies members of that list. If so, you can use an xpath (if it is already committed) or a datasource microflow (if it is not yet committed) to fill the list on page B. You can also show the list by association, but this will only work if it does not need attributes from the student entity to identify list members.