It's kind of hard to construct a fitting title, but here's the premise: An alien planet, the sapient species are very old and very advanced in technology, especially bio-engineering. They have of course achieved interstellar travel, and due to a biological factor I won't bother to explain in this question (unless it becomes relevant), they have achieved complete and stable world peace. They can cure almost any disease, have a renewable, efficient energy source and a healthy environment across the planet.
The problem, is that while most of the population has ventured into deep space to expand and explore, there is a small contingent remains on the planet. Communication between this colony and the space-farers is rare, and the story never focuses on them. This civilization is meant to sit in a state of what I believe would be slow scientific growth with no large economical or health problems for thousands of years before the story actually starts. Knowing that civilizations as we know them rely on some kind of progress or growth, what does this civ do? What is their goal/drive?
Side note: found it hard to select tags for this question, if you find any relevant, please add them.
Edit: Under no request, it occurred to me that maybe I hadn't clarified the size of the civ. It's basically one giant city with only a few billion people (still in world-building stages obviously so I can't say for sure, but I'd say at the very least, 1.5 billion, and at the very most, maybe 4 - 4.5, I'd like it to point towards the narrower end) this is of course due to a large amount of automation in agriculture and other such production.