How do I state that I worked at the same place more than once?
What is the most appropriate way to state that I have worked at the same place more than once over a period of time?
This is a no-brainer. Just list the job periods chronologically in your resume. If you worked the same place more than once, then just list it that way.
If you want to explain why/how that happened, your cover letter is the best place to do so.