To enter the quick preview mode, first go to particular recruitment details, and then go to Candidates tab there.
Next, click on the row with the candidate you want to explore, and the quick preview of the candidate in this recruitment will appear:
By clicking on the right and left arrow on your keyboard, you can browse the profiles of other candidates in this recruitment.
The quick preview is available when browsing the candidate's list on a particular stage. If you click on the row when visiting "All" list, you will be redirected to the full candidate profile.