Trim a group of objects

Hi guys,

I probably have a trivial question for you but I can't find an answer in our talk section/ google/ youtube.

I created this tyre in grasshopper and now I would like to delete everything which is outside of this box (the box is green marked).

The tire is a rotated surface + objects which are arranged on this surface. I grouped everything and now I would like to cut/trim it with the green box.

I'm usually using "SolidDifference" but it's not working.

It would be awesome if somebody could help :)

thanks!