Value over the last two dates of a Filter list

[Tobschmi]

Hello, everyone,

I have set different filters in a table, the data looks like this:

Id	Purchase date	Purchase price	Difference price
1000	11.10.2019	0,71	-0,09
1000	02.09.2019	0,80	-
1000	09.07.2019	0,75	-
2000	11.10.2019	1,25	0,12
2000	02.09.2019	1,13	-
2000	09.07.2019	1,20	-

What I want to do: I always want to calculate the difference between the last two purchase dates. I want to display this in the column Difference price.

I have already tried =Date(Max(Date)-1), but unfortunately I can't get any further. Can anyone give me a hint?

Greetings Tobias

[tresesco · Accepted solution]

Try like:

FirstSortedValue(Total <Id> [Purchase price], -[Purchase date])
-
FirstSortedValue(Total <Id> [Purchase price], -[Purchase date], 2)

[Tobschmi]

Thanks a lot, works perfectly!