DAX measure to MDX measure

Question

I'd like to write a MDX measure for a Pivot Table connected to an external Power BI dataset. What would be the equivalent formula that does same thing this DAX formula does?:

Speed_Filtered = 
CALCULATE (
    AVERAGE ( Playback[Speed] );
    FILTER (
        Playback;
        AND (
            Playback[Speed] >= 5 && Playback[Speed] <= 60;
            Playback[Pendiente] >= -9 && Playback[Pendiente] <= 9
        )
    )
)

Or if that is too complicated, this DAX formula:

Speed_Average = AVERAGE(Playback[Speed])

I suppose the filters can be applied just using the Pivot Table filter fields.

Here I add some images for some extra context in case I didn't explain the question thoroughly enough, since I don't really know what I'm doing:

Pivot table fields

Continuation of pivot table fields

OLAP tool options in Spanish

Calculated MDX measure window

The real end goal is to be able to populate this Pivot Table with the average speed value by day (ShiftInfo Date field as COLUMN field and New MDX Measure as ROW field) since Excel won't let me use the Playback Speed field as a value field:

Pivot Table to be populated with Speed values

As for what I've tried: I tried searching on the Internet for some formula template but always ended up getting errors, maybe due to syntax or something. I don't really know how to write MDX, so I can't really tell what went wrong.