Questions Left Join w/filter on right table

hello,

I am having trouble joining accurate information and would like to know if i am missing a key part to the relations.   my goal is to pull in only ARTran detail for a filtered amount of time (90 days here)  and connect it to inventory tables as shown in the screengrab. 

I was using Conditions to accomplish this, but realized it was filtering my results to only SKUs with sales in the last 90 days vs our entire SKU List w/filtered sum of items sold by SKU in the last 90 days.    i am attempting to use a filter on the relations function now, but cannot seem to accomplish my goal.

 any assistance would be greatly appreciated.

kind regards,

Pete