To locate these Opt Out flags for a member access the account via Member Inquiry then click on the Member Data tab at the top of the screen.  At the bottom of this box you will find the 3rd-party opt out and CU contact opt out information. 

If you need this information for all or multiple members, try Tool #100 "CU*BASE Report Builder (Query) to build a custom inquiry.  This information will be found in file MASTERL, field names MT3RDOPT for 3rd Party Marketing Opt Out or MTCUCOPT for CU Contact Opt Out.