Steps to reproduce:
In Control Panel
1 - Select the Global scope in content section.
2 - Then select Documents and Media link and upload a file.
3 - Click on the Move option of the uploaded file
4 - On the Move view change the scope to Liferay site
5 - Click on the Select button to select the folder
You'll be able to select any folder that belong to Liferay site.
Expected behaviour: User cannot move documents between sites.