When I use the region filter from the primary source the 'Opening' and 'Closing' bars do not work. he return a 'TbC' value rather than EMEA. So when I apply the filter it works on all the bars except the opening and closing bars. These need to be included but at the lower values...if you use the scaffold region, apply it and then show it, you will see what I mean.
Below is a shot of when I apply the EMEA region - both the opening and closing bars have disappeared when they need to be there
Any ideas on how to change the dimension calculation so that if the 'blend' value in the scaffold = 'opening' it should result in whatever filter has been applied?
Sorry, i'm afraid i'm not understanding your issue.
What i see is: TBC is how Yuri named Opening/Closing.
You have on your dashboard only EMEA and TBC. You can't call Opening/Closing of EMEA because you could have other regions, then you can't region. If you had more than one region, you can use parameters in order to don't filter Opening/Closing when filter Region.
It would be something like this:
Couldn't you use Blend as filter?