Getting last week (shift specific) data to display in a table

Hi, I also watched this video - Setting up Time dimension effectively for previous N Days display - #2 by sam.mckay

And I am not grasping the concept to solve my scenario. Need some guidelines. This is my last visual for my report needed for Friday (8/2/2019) Demo! :frowning:

for some reason , the SELECTEDVALUE() will not ‘stay’ in my sub-sequence FILTER statement.