Previously, the Realize Instances node would always realize everything in the geometry.
Now it's possible to more selectively realize parts of the geometry:
* One can choose which top level instances should be realized.
* The realization depth can be controlled per top-level instance. For example, if there are
5 top level instances, each of which contains 10 other instances, it's now possible to
realize only one level so that one ends up with 50 instances.
Pull Request: https://projects.blender.org/blender/blender/pulls/116582
1db538683d