To present the children of nodes in a new window:
The outgoing level arcs of the selected node(s) are followed one level to obtain the children nodes.
A new Children window appears, presenting all the children nodes of the selected node(s), with relationships among the children nodes shown by various types of arcs from one child to another.
Tip: If the node is a non-leaf node in the subsystem hierarchy,
you can double-left-click on it to present the children.