see friendship

 See Friendship  is a (currently silo-only) feature that shows a timeline of posts (like notes, photos, events) that are in common between two people, so far only implemented in Facebook.

Facebook
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.
 * https://www.facebook.com/tantek.celik?and=aaronpk
 * https://www.facebook.com/aaronpk?and=tantek.celik

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.:
 * http://aaronparecki.com/links-to/tantek.com