That solution has been working for for a while, but now sadly I have some common use cases where it does not, and the search works in Contacts.app but not Alfred.
First, the more common case. Say I have a contact "Michael Smith" with nickname "Mike." If I search in Contacts.app for "Mike Smith," Michael Smith's contact comes up with no problem. If I search for "Mike Smith" in Alfred, however, I get no results. I can search for just "Mike" (or any nickname), and I see all the contacts with matching nicknames, but as soon as I add the last name (or part of it), Alfred cannot find the contact.
This also means the special character trick does not work, because I have a lot of people named Kübra in my contacts, and I gave them all a nickname of "Kubra" (no umlaut). But when I look for Kubra, I get about 20, so I figured I would add the first couple characters of the last name to narrow it down. That gives me zero results the same way "Mike S" would not find someone with nickname Mike and last name Smith.
In the more second case, the workaround is to scroll down until I hit the right one, but in the first case, the only workaround is not to use nicknames. In any case, that behavior is inconsistent with the search in Spotlight, Mail.app, and Contacts.app.
Thanks!