Hi Zeglash,
Welcome to the Answers community.
From your post, we understand that you have one workbook stored in SharePoint online and other on your local computer and you want to link both, so any data changed in the workbook stored in cloud should reflect in local workbook, correct?
To link both the workbooks, you should use Excel desktop application. We can’t link directly from Excel for the web.
Once you open both the workbook in Excel desktop application, you can use Data tab to connect to external data.
- In the source workbook, click on the Data tab, then Get Data > From File > select From Workbook.
- In the Excel Browse dialog box, browse for or type a path to the file that you want to query.
- Click Open. If your source workbook has named ranges, the name of the range will be available as a data set.
Reference: Import data from external data sources (Power Query)
When you are connected to an external data source, you can also perform a refresh operation to retrieve the updated data. Each time that you refresh data, you see the most recent version of the data, including any changes that were made to the data since it was last refreshed.
Besides, you mentioned “ I have attempted to use "From Web" and "Get Data > From SharePoint Online List" and have been unsuccessful with both.”, this option helps you connect to your SharePoint list, since you want to connect Excel workbooks, this option will not work in this scenario.
If you need any help, let me know. Have a nice day and stay safe😊
Regards,
Neha