Within Teamwork Projects you can set privacy on links added to your project so only certain users can access them.
You can set privacy on links when first uploading them to your project, or by editing an existing link.
In the link modal, go to the privacy tab, where you will be able to choose who to include.
By default, privacy will be set to Everybody on project.
You can also set privacy to a particular company or companies, some individuals in one company, or some individuals across different companies.
Note: Site administrators in the owner company will always be selected (gray), as their permissions override privacy by default and they will always be able to see the item.
To change the privacy of an existing link, click the Edit pencil below the link name in the project's Links tab.
For more information on links see: Adding a link