Sum Values in Matrix based in another value in that matrix

Hi TomMartens ,

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Q: "Please explain why there are only three rows of the forecasted version, meaning why 2025 F4 and 2025 F5 are not included in the result."

A: I dropped the following versions in the example as they don't add additional information. The sequence would continue...

 Q: "Why is there no space between the year and FX value in the expected result, if the first image shows a space between 2025 F3? "

A: This was a typo on my behalf, I probably fixed it at some point between the posts. The Version would be any string for that matter

Q: How does the slicer affect the expected result?
A: The slicer dynamically  'offsets' the distance between the date/week the forecast was created and  forecastedweek the forecast value is applied to.  
   i.e. if the slicer sits at 4: The Forecast Value for the Forecasted Week must come for the forecast that was created at least 4 weeks earlier. So if I look at week 12, and 

      the slicer sits at 4, the forecastvalue from the version that was created at or just before week 8 is applied.
     if the slicer sits at 8, the forecastvalue from the version that was created at or just before week 4 is applied.

Q: what numbers are summed?
A: The Forecasted Value is summed.
For completion:  Also summed are the actuals for the same periods and then variances and counts etc are calculated, but I don't expect any issues with that at this point.  

 The very final endresult (depending on the slicer setting)  should look somewhat like this 

Where the 'mean forecast error' is calculated 

∑n(Actualst - Forecastt)

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