Trying to use ExtractSubset filter, but off axis

I am trying to use the ExtractSubset filters to highlight specific parts of a VTI dataset. The filter is working fine for regions that are aligned with the axis of the VTI files, but I have some rectangular objects that are off-axis at funky angles. I want the freedom to define the ExtractSubset filter’s orientation and size, but I am stumbling on how to do that. Size only?

Help, please!

If it helps someone understand. I have tried chaining in a “Transform” filter but that seems to blow up any of the volume renderings.