Two point clouds, one selection, without losing context

[mwnz]

I have imported two point clouds as geometry SOPs. I would like to construct a system in Houdini that allows me to make a selection of the combined point cloud as if it were a single cloud. I would then like to apply transforms to the selections, using information specific to the individual clouds.

So my goal is:
- user only needs to make a single selection in the overlapping cloud region
- the post-processing of the selection needs knowledge of which geometry the individual points came from

Is this possible in Houdini? Can anyone offer me guidance for how I might achieve this?

Thanks! 

Edited May 16, 2016 by mwnz