That's correct; there is no single-clip looping function as there is in After Effects. Duplicating the footage item in the timeline is the way to achieve what you want. However, you might consider creating a new sequence just for that background element, and then nesting that sequence into your final sequence. It will just make clip management a bit easier and your final sequence somewhat tidier.
You could also export the "looped" clip as its own video clip, and reimport that into your project, but that might be wasteful of time and space, and not provide the same flexibility that nesting does.