Grouping
You can define groups in EX3. Under properties pane in visibility tree, you will see the following parameters you can modify: name, role, applied property, and grouping. Click on the pencil icon to define a group for the layers.
These groups have a name and visualization options and can be assigned to volumes in a similar way to materials (and are also similarly stageable). By default volumes will be visualized by their group properties if they are grouped, but this view option can be toggled to instead visualize material colors. The groups can be seen in the Groups tree, which also allows users to select all nodes in a group. Some things, such as field points, are not currently groupable.