I was on the DNA ancestry page for my "not viewed" matches. Below the pull down for filtering between, "all"..."has a hint"..."not viewed"..."starred" was a box to enter a surname and then another box next to it where you can enter a location. Then you click on "filter" and it pulled up all of my DNA matches with the surname I had entered. For example, I entered in the surname "Dunn" and all of my matches that also had "Dunn" in there trees appeared.
I logged of my computer for the night and when I logged back on this morning those options were no longer on my ancestry DNA page.