Auto Groups with Uvs

From ZBrush Info

A new option has been added in the Polygroups menu: Auto Groups With UV. It creates a polygroup based on the UV shells of the model. This function is different from the UV groups which create polygroups based on the different UV spaces. (between 0 and 1, 1 and 2, etc.)

Create polygroups based on a multi UVs model:

1. Load or import a model which has different UV shells.
2. Optionally, switch in Frame view (Shift+F).
3. In the Tool >> Polygroups menu, click on the Auto Groups with UV button: ZBrush automatically create different Polygroups, visible when the Frame is enable.