There are two ways of layer grouping.
First, you can start with an empty folder:
- Open the "Layers" dialog and apply the "Create New Group" command.
- Select the necessary items in the left panel and use "Add Layers to Set" command to put them into the created group.
The second approach is creating a group from selected layers:
- In the Layers palette, select one (and only one) layer.
- Open the "Layers" dialog and, in the left panel, choose the layers you want to group.
- Apply the "New Group from Selected" command (screenshot).
- Later on, you will be able to add new layers into the group with the help of "Add Layers to Set" command.
Please, note that when you add a new layer, it appears at the very bottom of the group.
Although you can change the stacking order of the nested elements with the "Move Forward" and "Move Backward" commands, as a rule, you'd better order the layers prior to grouping.