Those are the correct folder-trees for both Mac and Windows.
Going through Finder or Explorer to get "there", for some users the LUTs folder isn't created by the application on installation. So you may or may not need to create the LUTs folder in each spot you use.
You DO have to create the Technical and Creative folders in those spots. Place your LUTs in the Technical folder for use in the Basic tab, or Creative folder for use in the Creative tab. IF you rename your LUTs by say adding a letter or number prefix, you can both see to it that YOUR LUTs show first in the lists, and even group your LUTs by type of look/effect or source.
On restarting Premiere after your LUTs are in place, they will now appear in the drop-down lists in the Basic and Creative tabs within Lumetri.
Neil