Within the Rank Tracker Overview page, and under Keywords tab, head to the keyword that you are looking at and then click "SERP".
A drop down with full view of the SERP results for that keyword will be shown.
Within each SERP, you can see including information like the Ahrefs Rank (AR), Domain Rank (DR), URL Rank (UR), No. of Backlinks, No. of Domains, Traffic, Keywords that are ranking for the page, Top keyword and Search Volume.
Simply click on the number reflected under Backlinks to access the full report.
The Backlinks report within Site Explorer will be pulled up for you, which shows you backlinks that are linking to that page.
By clicking on the number reflected under Domains, the Referring Domains report within Site Explorer will also be pulled up for you.