Calculate filtered by measure

Hi, sorry that I forgot to share some data:  The file is also attached. 

In this example below I have a material ABC which we have stocked in 4 different warehouses ("Plant"). However, only one warehouse is to be regarded as the main warehouse. Please check in the in first table from above the measure "MW ind". In this example here it is "Plant" 4.

Then in the second table I have again material "ABC" and here I would to show only the excess stock which is maintained for our "Main" warehouse. However, as you can I get odd results. I should have gotten 0, but PBI returns 5000. Does not make sense.

Please note that I am fully aware of that a calculated column would be the easiest. But our IT does not have the ressources at the moment. In addition when to tried to bypass it by creating a composite model I got a run time due to missing processing power.

Do you see any smart way for a workaround?