I appreciate this comment, pretty common on stock/inventory values compared to sales totals. From what I have been told its an all or nothing solution on the database here:
Semi-additive measures (stock amounts) make it difficult to have in same DB. As a workaround I have had to create two DB’s one housing the values I do not want to total such as stock values and the other with sales values that I do want to total. I then place them on a dashboard and since it is using the same dimensions it can filter correctly but its on two widgets rather than one.
To permanently rectify this, I believe this needs to be done on the DB design (where you place the measure) and mark it to not total, as already said currently its all or nothing with the above switch…unless someone else here can provide a better solution.