I did a bit of trial and error …
I used the basic search box which is at the top of any profile. I entered Alfred the Great in the first name box, and got no matches at all. I then tried just Alfred, and got over 150,000 matches, and sorted these by birthdate. Interestingly many of the results were vastly different from “Alfred”, for example, Abu Bakr al-Siddiq ibn Abi Quhafah. I then clicked the radio button for exact matches, which reduced the number of hits to around 90,000, and sorted by birthdate. Alfred was then at the top of the list as might be expected since he was born in 849.
Something to note, Alfred is given a last name which is typical for nobility (which is derived from the Royal House or dynastic name); if he were an ordinary person without a surname or with an unknown surname he would have been “Alfred Unknown.” Although there are some other peoples that have assigned surnames.
So, with a bit of creativity, you can make the search work.