If you have multiple presentations open, you can cut or copy a Sub-folder and paste it across presentations.
Note: Sub-folders with mobile slides (.mprs) cannot be pasted into presentation (.prs) files.
To copy and paste a Sub-folder across multiple presentations
The Sub-folder will be added as the first Sub-folder by default. If a particular Sub-folder was selected when the copied/cut Sub-folder was pasted, the new Sub-folder will be added below the selected Sub-folder.