Today I had to figure out what domain groups a user was a part of.  I had to find out if a particular user was part of a specific domain group or not, so that I could verify if that group was part of the server’s local administrators group. And if it wasn’t, then I [...]

Sometimes on your workstations the group policy doesn’t take affect. Or you need it to take place immediately. The command to invoke this is gpupdate /force