In Sharing section of Document view you can manage all sharings of document.
Select the document from document list and click on Sharings tab 1.
Form has 5 groups of sharing depending how document is shared:
- Collections - document is in collection
- Users - document is shared to user directly
- Teams - document is shared to a team and it's members
- Organizational units - document is shared to organizational unit and it's members
- User groups - document is shared to user group and it's members
Share document simply by clicking on + Add link in appropriate group.
For example clicking on Add Collection 2 will give you option to add document to one of available collections. Remove document from collection by clicking on X icon 3. This gives you control over document's membership in collection without opening any collection.
Sharings have name, icon indicating permissions and number of users who have those permissions 4.
Manage permissions through popup 5 where you can choose to remove the share, grant only view permissions or grant permissions to edit the document.

Like and share