I think what he's saying is to circle an object while keeping pointed towards it.
Very easy to do (harder to do SMOOTHLY) when flying FPV, but I imagine it could be quite a challenge to do LOS.
In my pilot's licence when had a series of test manoeuvres to complete:
- Fly out 30 metres and hover over a cone ... and be within a 2m radius of it. Really tests your ability to judge how far away you are, and it's way harder to do than you think. You'll invariably be too close or too far for a while. It pays to have a spotter off to the side of it the first few practice times to tell you when you're over it.
- Fly a figure eight between two cones placed to your left and right. We were allowed to do this maintaining a nose out attitude, but it's fun to practice doing it by flying it keeping the nose in the direction of travel (like a plane would have to fly it).
- Fly a horizontal square with nice neat corners.
- Fly a vertical square with nice neat corners.
- Fly a vertical square but with a triangular base where you take off at a 45 degree angle, do three sides of the square, then land at a 45 degree angle back to launch point (tests use of two sticks simultaneously).
- Fly away from yourself, switch to ATTI, then turn around and fly a straight line back towards yourself (sucks to do in high side-winds like on my test).
There were other things, but I don't remember them all.
Whatever you do use, I'd suggest not flying it with all the gimbal and camera on board. No matter how soft you obstacle course is, gimbals don't like hitting the ground from any height, and even soft obstacles have potential to bring your bird down.
A supply of helium balloons tethered just with paper streamer might work, at least hitting that isn't likely to stop your prop or tangle in it, and you'll only lose a helium balloon.
If you wanted to go really fancy you could try the fan filled tubes of cloth like they use for the red-bull aerial slalom courses. A couple of old cheap hairdryers and some lightweight cloth tubing should work, but powering them is another matter all together if you're away from home.