Unable to select multiple layers and Encapsulate?

So, I watched a tutorial on youtube about using a skeleton and, I was following along of what the guy was saying and, when he said, select Encapsulate and,right click on the 3 layers,I was unable to do it. It only lets me select one of the layers and, there is no Encapsulate option.

This is the video


This is the time of the video where he explains the Encapsulate option.


It has been changed to more common term, :group. Pls refer to wiki.synfig.org/wiki/Group

and for all updated terms : 0.64 release, new terminology