When I open two files with identical file names in one group I get the folder path as expected:

As soon as I split my workbench into two groups and put the files into different groups, the folder information disappears:

@bpasero by design or oversight?
By design.
I don't have any data to back this up per-se, but I would think it would make sense to leave this on even after splitting. I think even if it's split that it's not clear where each file is living. Just my opinion though, not complaining :)
+1 for maintaining this behavior across groups.
The RoscoP.ActiveFileInStatusBar extension is not ideal, but helps for the time being within the focused tab.
May I suggest adding a setting to have either:
A workaround is to configure the new workbench.editor.labelFormat setting. No further work is planned otherwise.
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I don't have any data to back this up per-se, but I would think it would make sense to leave this on even after splitting. I think even if it's split that it's not clear where each file is living. Just my opinion though, not complaining :)