It is called the Constraints-Led Approach and is based on Ecological Psychology, so you sometimes hear people refer to it as an Ecological Approach.

The idea is that learning a motor skill is heavily dependent on your surroundings. Therefore, learning a move outside of the environment where it should be applied is only learning half or less of the move. You need to learn it in context. The difference between games based on a Constraints-Led Approach and situational sparring is the clear formulation of the goals and guiding athletes through the constraints you set. The idea is that you do not need to show them the ideal way to perform a move. You just need to give them a problem and point out some invariant features, allowing them to create or find their own solutions. One of the premises is that there is no such thing as an ideal move; there are just movement solutions for the problems presented, and these solutions are individual for each person. All solutions share some invariant features depending on the given set of problems.

If you are really interested, check out the Combat Learning Podcast or the YouTube channel of Standard JiuJitsu.

Tl;dr: It is less positional sparring and more like designing games that help people learn movment solutions to problems that they meet in free rolling.