You might also find your answer in the LastPass Enterprise Manual.
How do I share Folders?
To create a new shared folder, go to the Vault and click on ‘Manage Shared folders’ in the left menu. Click 'Create a New Shared Folder' button.
To share an existing folder, go to the local Vault > right click the folder > Share Folder.
Add a Folder Name and click 'Create'. After creating the Shared Folder, you can then add users to the Shared Folder list to share it with others.