Hi MM
Unfortunately, according to the LabView Help doc, neither the "Scaling and Mapping" or "Amplitude and Level Measurements" Express VIs are included in the Base Package.
😞I'm assuming that you are using the Getting Started with LabView manual
linked hereI can't say I understand why the tutorial should reference VIs that are not included with your package, it may just be an oversight. However, generally you can workaround the Express VIs as you have done.
If you get stuck you can always post another question on the forum.
Good luck.
Regards
Neil