Problem with nested lists

[arminganic-iteratec]

Currently, I am using this library to sort a list and everything works fine. Now we want to have a nested list and sort every list independent of each other. For that I thought that I only have to use the directives in the sublist but give it another group name. But unfortunately that doesn't work as expected. I've attached a video that shows the behavior.

Am I doing something wrong or is this not supported yet?

https://github.com/kreuzerk/ng-sortgrid/assets/90381428/ac618b10-92f9-41f2-a026-f002be470426