Groups like Accounts, Regions or Subnet are collections of other resources that can be expanded or collapsed to show or hide their contents in the diagram.
Like folders on your filesystem groups can be "opened" (expanded) and "closed" (collapsed) to display, or not display, the topology inside of them.
By default groups start off collapsed, like this:
Clicking on a group icon will show the Resource Detail Panel.
Click on the Group label to expand the group and display its contents:
Here the expanded group contains one customer gateway node and three "sub" groups of type 'Account' that we can now see: demo, seller-london and testing.
To collapse a group again, click on its label.
The "Expand All" Tool
You can also automatically expand ALL subgroups using the "expand all" tool in the top-right corner of the screen:
To use this tool simply select a group first, then click the "expand all" button shown in the top-right corner.
Be careful using the 'expand all' tool on groups containing large topologies as your browser performance might suffer.