In my case Server always says "(Local)" if any child test ran locally. I think this should be a comma-delimited list like Category. Next best thing would be leaving it blank.

If I'm filtering for failed tests only, the current behavior is really a bug, because all of the failing tests may have ran on one node server that isn't (local), yet the grouping row alone still says (local). So it makes scanning the server column to troubleshoot issues (in this case node server dependency config issues) confusing.