Scaffold Date in Power Bi

I posted a similar questin before but now I now the solution is to create a scaffolded data set but still don't know how to do it in Power Bi.

Can anyone help with the query below:

I want to be create a graph that shows open or active cases in a point of time.

I two tables: Cases and Master Date.

Cases have the following important fields:

Opened date – the date that a case was opened

Close date – the date that a case was closed

Master Date table has dates from 1/1/2019 until 31/12/2025. It is like a reference table.

This table is not related to my main table in any way.

I want to create a new column to define the relationship between the two and in the process create a new column which will give me many rows of data for each row to tell me the Active Date

e.g.

I expect the expression is something like this

IF

Master Date [Date] >= Cases[Open On]

AND

Master Date [Date] <= Cases[Close Date] (And if Close Date is Null make it Today)

THEN

SET Active Date to Master Date??