SharePoint Online (SPO) and OneDrive For Business (ODFB) provides a very simple way to give access to any file or folder directly in the document details panel by means of the “Grant Access” setting:
When the user clicks that option, a small dialog to configure file/folder access is shown. In this dialog we can specify the following setting:
The user or users we are going to grant access to the particular file or folder.
The permission (Read, View) to be granted.
If a notification is going to be sent to the people we have granted access.