Do you wish to duplicate these two systems? Or do you wish to copy only these two systems to a fresh project (such that the new project only has these two systems)?
To duplicate: You can right-click on Cell 1 of System E (where "Static Structural" is written) and choose Duplicate. You then get the option to either retain the links to system D or create an independent system. Similarly, you can duplicate system D.
If you wish to copy these two systems to a fresh project, you can use the "Export System" option from the menu that shows up when you right-click.
Hope this helps.