Can't get objects to orbit objects orbiting objects, orbiting objects....

[oisiaa]

I started the Earth Moon simulation and then added Apophis to orbit the Moon. That works. But I can't then get something to orbit Apophis. I tried to get a bowling ball to orbit Apophis, but it instead orbits the Moon and acts like Apophis isn't even there. Do I just need to drop it to a lower altitude so that Apophis' gravity dominates?

[Bla]

You can see which gravity dominates by showing hill spheres, I think. Try placing it inside the hill sphere of Apophis, and placing Apophis further from the Moon will probably help too.
Does that work?

[atomic7732]

Also make Apophis have more mass, and put the objects in the inner half of the Hill sphere, objects outside of teh first half are usually very unstable.

[Dan Dixon]

Move the moon out much further from the Earth and then place Apophis even further from the Moon.

They're simply too close as you describe for the orbits to remain stable.