How to "Drill Down"
 

I am a new OmniGraffle user and have a few questions. I searched the forums and got some answers, but there are some things I am still a bit unclear about a few things.

I have made an ERD diagram and I want to be able to "drill in" or "explode" so I can get detail on a process or a data file. How do I do that.

I have been successful exporting to visio and then importing back in, but is there anything that in OG that Vizio won't support or vice-versa.

Finally, I found some ERD objects but they aren't so attractive. What other stencils do people use for ERD.

Thank you very much.