If you are using the platformer or 8direction behavior you can use the 'simulate control' actions to move AI around according to event logic.
Sines can also be used to move enemies, though that's a little more complicated. Here are some links:
Here's a capx I set up w/ invisible barriers to contain enemies (they just walk back and forth like goomba's)
https://www.dropbox.com/s/xkd1uefwp8ffb ... .capx?dl=0