I have 3 dimensions and 2 expressions in my straight table. I want to put the sorting criteria in all my dimensions and expressions. I have enabled sorting in the Sort Tab but in my table it's only sorting by Pocs.QTY.
If I understand you, you want to sort your 3 dimension to your preferred choice.
In your Straight Table go to -> Sort tab -> Select the First Dimension -> Check Expression -> Click on the Eclipse (...) and type in Match(DimensionValue,'Date','Date','Date','Date','Date','Date'). You will have to repeat this exercise 3 time for all your Dimensions.
Please have a look at the Sort Tab and make sure all the fields have a single sorting criteria selected. Also it would be good to check the Group dimension PeriodDate.Date to see if you have defined sorting criteria for the fields too.