MDX Calculated member filter by dimension attribute and member value

Question

I have MDX (similar to one questioned and answered here):

(
[PX Market].[PX MARKET NAME].&[Elbas],
[Measures].[PX QUANTITY]
)

It works for me (it filters measures to value "Elbas" only). But I need another filtering - to have only values which are < or > than 0. There shoud be some condition similar to "[Measures].[PX QUANTITY] < 0". But I do not know how to implement it.

Thank for any of your advice.

Ondra

Table looks similar like this:

PX_MARKET_NAME; PX_QUANTITY

Elbas;  5

Elbas; -3

Elspot; 4

In result I need only 2nd value (-3). Which belongs to Elbas and is smaller then 0.

So far I tried this, but it is now working :(

FILTER
(
[PX Market].[PX MARKET NAME].&[Elbas],
[Measures].[PX PURCHASE]
) < 0

Answer 1

Try that:

IIF(
    ([PX Market].[PX MARKET NAME].&[Elbas],[Measures].[PX QUANTITY]) < 0,   
    ([PX Market].[PX MARKET NAME].&[Elbas],[Measures].[PX QUANTITY]),
    NULL
)