This question i have asked before in the forum. But maybe this time i succeed in communicating more clearly what i mean with it and want to know.

I want to use groupselection for masking in blendshapesSOP for asymmetric facial (left and right) features in a random character generation. (Without altering the geometry by splitting in half and fusing back together). Masking the left part and right part of the geometry and blending those back together so the blending can be slightly suppressed.

I also want to be able to clean up the blending if there are points that have in more than one shape extreme positions and suppress additive effects with group masking.

As for your first question, there was a bug with the Group parameter that has was fixed in 7.0.326. Try downloading a later version from here:
http://www.sidefx.com/download/index.php [sidefx.com]

As for your second question, I'm not quite what you mean. You can create a group from taking the “intersection” of multiple groups. Then you can just use this group to do your “clean up” (whatever that may be).

Thanks, Edward.

I'm gonna do that.

The last part of my post was about something i also wanted to use the group “masking” for in blendshapesSOP.

Objects that have parts with morphed geometry that overlap, the points on the edge of overlapping areas get a translation from both “active blendshapes”. They stick out, peak.
you could probably use painted weightmaps to counteract that but i'm not looking into that yet.

You get the same in lightwave with (unmasked) copy and pasting of morphmaps.