When sharing a document set, you also grant access to all sub documents and sets. Permissions are inherited, but can be overwritten for a specific document.
To share a document set, select the desired document set:
Select the “Members” tab in the navigation:
You will see a list of members who already have access to the document set. The members will have access as per one of the following:
To invite a new member to collaborate on the document, select the "Invite a new member" button near the top left corner of the screen:
You will see a pop-up similar to the following:
Enter the email address of the user you wish to invite. This can be any email address; if the user is not a member they will be sent an invitation email.
Select either "Owner", "Contributor" or "Viewer" and press "Invite". The user will receive an email and the document will appear in a special collection:
All documents in the document set will then inherit these permissions. If we select the members tab of a document, we can see the inherited permissions:
You can then assign permissions specifically to the document without impacting the document set if need be.