select b.*, a.*

from membership_record_tbl a

INNER JOIN sales_log_tbl b
      on a.member_id = b.member_id and a.company_id = b.company_id
      
where b.purchase_dt not between a.membership_effective_dt and a.membership_term_dt

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

SELECT a.*
FROM sales_log_tbl a
LEFT 
JOIN membership_record_tbl b ON a.member_id = b.member_id 
                            AND a.company_id = b.company_id 
                            AND a.purchase_dt >= b.membership_effective_dt 
                            AND a.purchase_dt < b.membership_term_dt + 1 --Do you know why you should use this?
WHERE b.member_id IS NULL