This KB is intended for modifying the "Default Attributes" package for a particular ResourceKind.
The vSphere UI doesn't have dashboard per se, but does have different panes. How are you trying to view the metrics? Please attach screenshot of the view you're using (you'll likely need to use Operations : All Metrics in the vSphere UI).
What ResourceKind are you trying to add this attribute for?
Can you please post a screenshot of the attribute package and the metric you have selected? Include the name of the attribute package on the screenshot.