Filter for terminations in prior calendar week

Summary

I'm creating a termination report and trying to show which terminations were in the calendar week (Sunday-Saturday) prior from the week when the report was run

Content

Hello,

I'm trying to create a report that shows which terminations were from the prior calendar week. So far I've only been able to create the below formula to show terms for 1 week prior to current date, but it's calculating the past 7 days, not calendar week. I've tried changing the formula to use CALENDAR WEEK but to no avail. 

CASE  WHEN (("Worker"."Termination Date" IN (timestampadd(SQL_TSI_WEEK,-1,CURRENT_DATE))) OR ("Worker"."Termination Date" IN (CURRENT_DATE))) THEN 'Last Week' ELSE '' END