SAP HANA Studio: Create Time Hierarchy for Lumira

Hey,

I try to create a time hierarchy in SAP HANA Studio.

I have a graphical calculation view, I have created a level hierarchy there:

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I have an attribute "DateOfRegistration". Out of this I calculate 3 more attributes (Year, Month, Day), which are INTEGERS and I use them as levels.

But the problem is, that Lumira doesn't detect it as a time hierarchy. I want it like if you create a time hierarchy in Lumira.

Kind regards