OK, so here's how you do it.
First, create friend groups. To make it simple, make two:
Then, under "Settings", there's a setting for Privacy. In there, you set who can see what kinds of things (for example, Photos Tagged Of Me). There's a dropdown where you can specify only friends, or friends of friends, etc...but it also has a "custom" setting. So you can specify that either everyone but the group "Professional" can see, or only the group "Friends" can.
You can also set this type of privacy on photo albums you create.