How do I duplicate just one clip segment in Final Cut Pro?

I used the blade tool to cut my clip into segments. I want to duplicate one of the segments. When I select the segment and press command D, the whole clip is duplicated, not just the segment I wanted duplicated. Is it possible to duplicate just a part of a clip? If so, how?

Thanks in advance. Everyone here has been awesome!

[Re-Titled by Moderator]

Original Title: How to Duplicate a Clip Segment