Hello and welcome to the Community @Vincent_GUYADER!
First of all thank you so much for sharing your base—it’s always great to be able to see what you are working with.
So it looks like you have a link from the Student table to the exam table—and you are already using a lookup field to pull the exam date for each student:
If you are looking to pull the date for the most recent exam date for a classroom with many exams(I added two exams to the same classroom):
You can do so using a rollup field and the
MAX() formula to find the maximum date (or most recent) date of the Exams for that classroom:
Now looking at that table you can see the most exam date is the one listed in the “Most Recent Exam Date” field:
Let me know if I can help provide any more information, and if this helped answer your question please mark it as the solution .