I can't imagine why it wouldn't work, the underlying Windows APIs that supported the program when it was first released are still present in Windows 7.
I ran it on my non-domain 64-bit Windows 7 system and it correctly tells me whether or not my account is a member of built-in local groups such as "Users" and "Administrators". I'm pretty sure it would work fine with domain groups since the same API calls are used for both.