Seeking effective resume tips for showing two tours of duty at the same company

I'm banging my head against the wall trying to update my current position on my resume. I worked for three years at my company, left for two and now I've been back for another three. Additionally, I just got a promotion. My question is, do I include both my old position and my new position and show the two year break in employment or do I combine both tours of duty, since the job I left for and worked for two years will be the next entry on the resume?

I want to keep it short and sweet, but I don't want to make the mistake of leaving something out.

Any insights or examples would be greatly appreciated!