Managing Permissions within SharePoint Online

Open a Document Library - You may just be on a page looking at a WebPart of a Document Library. To ensure you're actually in a document Library click "See All" in the top right-hand corner.

Once you are in the actual Document Library - Check the checkbox next to the folder you want to manage, then click the “i” icon, then Manage Access

You can tweak access right in the pop-up that appears, but if you opt for more “advanced” way of setting up security for a folder, click on Advanced

From there, you will see a screen that will allow you to set granular permissions for a folder. By default, the folder inherits permissions from the parent (Document Library in our case). By breaking inheritance and removing/adding groups and users, you can set unique permissions for your folder and hide it from other users.

What we need to do is break that inheritance so we can set out own. Click Stop Inheriting Permissions

Click OK when you get a warning message

It will now state that This library has unique permissions – exactly what we wanted

Next, you can adjust permissions for this particular library. Say, for example, I do not want my team members and visitors to see or access this library. Just Site Owners should see it. So, what you can do, is remove those groups from this library. Don’t worry, whatever you do here only impacts the library, not the whole site.

Likewise, you can add specific users if you wish by clicking on Grant Permissions button. So in the end, your library might have unique access that looks like this: