Microsoft Bing is testing a feature in its search results page to anchor you to different sections of the search results. Microsoft calls this "On This Page" and when you click on an item on the left side bar, the searcher will be anchored down the search results page to that section.
This was spotted by Khushal Bherwani and posted on Twitter - here is a screenshot from Frank Sandtmann, a German based SEO, since I cannot replicate:
Here is a video Khushal made:
Finds in Bing - left side bar "On This Page"
— Khushal Bherwani (@b4k_khushal) March 17, 2022
Bing shows content on this page. by click on that tab it's scroll down to the result.@rustybrick pic.twitter.com/uJLrqNJXqg
Bing has been doing interesting things with the search results page including page insights and explore on this page - here is just one more.
Forum discussion at Twitter.
Update: Here is another variation:
Microsoft Bing test Content of wikipedia page on serp page. whene you click on it you directly go thru with that. pic.twitter.com/aWKtdfP6uJ
— Khushal Bherwani (@b4k_khushal) March 24, 2022