Files

I am trying to set up a Teams site that can be used by a project team that includes consultants outside of our company. I have added folders to the "Team" channel that I would like to share, but it appears that my guests have access to the general Sharepoint site and when you click on the "Files" tab on the left of the screen it shows documents that are not included in the folders that have been setup for the specific Channel.

Here is where I am referring to the tab on the left:

The files listed in this tab is different from the files listed here, which shows the correct files to be shared with the team.

I need to restrict their access to the information only on the Teams site.

Any help would be much appreciated.