Multiple file name search doesn't work

In the 6.x search tool I could choose File Name > Contains > and then add a list of files names (0001 & 0002 & 0006) and it would show only those files. This doesn't seem to work in 7.x. For starters it doesn't event give a File Name option. It seems Display Name is the new equivalent, but I've tried formatting the list of file names in every imaginable way but nothing works.

On the topic, why use Display Name rather than File Name, and why use & as a list separator rather than a comma. From a usability standpoint this makes little sense to me, but maybe that's just me.