How to return the previous date using a parameter selected range

[Nellis5]

I'm having trouble creating a measure to display previous dates from an order date column based on a parameter. I tried to make it a calculated column until I learned that parameters don't update in those columns. Ultimately, I'd like to be able to compare the previous date against the current order date in a row and calculate the difference (again inside a measure).

Using Window functions and offsets have gotten me close, but I keep ending up with a blank column. Alternatively, some of the measures I've tried produce values, but don't give me the previous (see measure below)

Previous = MINX(WINDOW(-[Number of Orders Value],REL,0,REL,OrderTable,ORDERBY([Order Date],ASC),,PARTITIONBY([Customer]),MATCHBY([Order Number])),OrderTable[Order Date])

Desired

When the parameter([Number of Orders Value]) is set to 2

Customer	Order Number	OrderDate	Previous
1	Foo1	9/10/2024	9/10/2024
1	Foo2	9/12/2024	9/10/2024
1	Foo3	9/13/2024	9/12/2024
1	Foo4	9/19/2024	9/13/2024
2	Bar1	9/12/2024	9/12/2024
2	Bar2	9/15/2024	9/12/2024
2	Bar3	9/19/2024	9/15/2024
2	Bar4	9/20/2024	9/19/2024

[Nellis5 · Accepted solution]

Sometimes it just takes asking to find the answer. I was very close with the DAX I posted, I just had to add "ALLSELECTED" to the relation to make it work.

Final DAX, Change in bold
Previous = MINX(WINDOW(-[Number of Orders Value],REL,0,REL,ALLSELECTED(OrderTable),ORDERBY([Order Date],ASC),,PARTITIONBY([Customer]),MATCHBY([Order Number])),OrderTable[Order Date])