Once you are logged in to your account, and on your Portfolio page, you can view a page that lists all your review periods to date.
To visit this page, you can either click on the pink date of your current stage of training in the box at the top right of your Portfolio overview page:
When you are in the ESR preparation section (by clicking on Prepare);
you can click on List reviews:
To review the summaries of your past reviews, click on View to see more details: