Column from sharepoint online does not show value

That just means the data are stored as a list and can be expanded further to get to the results (Records and Tables are the same).  In the query editor, you can click to the right of the word list (not on it) to see what's inside as a preview.  In the column head you should see an expand button on the right hand side.  Click on that and choose Expand to New Rows.  You may see values, Records, or another list.  If a record, click the expand button and choose the fields you want, etc.

Regards,

Pat