How to deform a hierarchy/group of objects?

Hi all,

I have a group of objects, some are in a hierarchy within the group. I was trying to create a layer and deform the group/hierarchy but can’t figure it out. When I joined them they still moved individually. It wasn’t until I voxel remeshed that I could deform correctly. Is there a way to not have to join/voxel remesh to do so because I would still like to have the control of the hierarchy?

Thanks