Linking Workbooks

I have a source workbook in SharePoint that links a table to a destination workbook, also in SharePoint. I am sharing the destination to an external user because I do not want the external user to have access to all of the other data in the source workbook. However, when the source workbook is closed, the data does not show up in the destination workbook. How can the data always show in the destination workbook and dynamically update, even when the source workbook is closed?