This would entail to copy your project libraries into a common place and adding them to the global library list.
They will then be added to the global fp-lib-table file in the KiCAD program settings folder.
Just copy the Lib-1.pretty, or Lib-2.pretty, or Lib-3.pretty folders into your new project folder - probably still have to add them manually to the project as project libraries afterwards though.
This is because there is a fp-lib-table file in the project folder which contains the local project lib links.