How to get data from query table created only connection

Good day Yosuke_KAZEOKA ,

Table (a) is created as "only connection". If you load it to a table then you could connect Power BI to the workbook containing (a).

Hope this helps (and that it isn't a stupid suggestion as there may be a reason you have had to use "Only Create Connection").

Hi Yosuke_KAZEOKA ,
Based on your description and the flowchart provided, it looks like your initial goal is to get multiple .csv files from SharePoint.Power BI supports getting data directly from SharePoint, you can click on the Get data option to select the SharePoint data source. You can refer to the following two official documents for specific steps.
Create a report on a SharePoint List in Power BI Desktop - Power BI | Microsoft Learn
Power Query SharePoint folder connector - Power Query | Microsoft Learn

Best regards,
Albert He

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly