On user profile pages, when logged in, Facebook provides a "See Friendship" option (like in a menu option from the "..." button/menu over the header image) that shows a "See Friendship" page, e.g.:
This appears to be commutative as both URLs show the same result.
Similar IndieWeb Examples
There are no IndieWeb Examples of the "See Friendship" feature yet, however, there is at least one implementation of a similar feature.
Aaron Parecki on his site aaronparecki.com has a "links-to" feature that shows a timeline of all posts where he has linked to a particular domain/person, since 2014-10-13. E.g.: