Hi @Anonymous ,
Do you want to copy folders from Library2 to a folder you’ve created on Library1?
Do you want the flow to be triggered when a file/folder is created on the root of the library?
However, the trigger When a file is created (properties only) will be triggered for the whole library if you leave the Folder field blank.
In your scenario, the flow will be triggered whenever a file/folder created in the library, including the files created in the subfolders.

Hope this makes sense.
Best regards,
Mabel