This drill is fun and great for children and adults alike.
We take a rope long enough to hold in both hands as the middle is on the ground.
Pass through forward and back. make the rope between your hands shorter by two fingers widths. Repeat.
As you progress, you will find it harder and harder to pass through. Use the angles of the body to pass and moving your legs and hips beyond the linear path.
You can see a chain version of this drill in this video:
and there is a second part with much more work: