I know there are some in the US military who prefer to attend AA meetings away from the military base. But for myself and others I know anonymity hasn't been an issue. If my boss or someone I worked were to walk into a meeting and I was there I would simply say hi.
In my first few years of sobriety I felt a bit worried. Once a co-worker surprised me at a meeting but he never said anything to others at work. He also didn't stick around very long. I only saw him twice.