The Visible To: date field in the review record in GIFTS drives when the review is visible until before it no longer displays in the portal. To make a particular review disappear, set the visible to date to be a date before the current day. 

You can set up your reviews when you create them to only be visible to a particular date so that you do not have to come back and adjust this record by record. 

Please note this is not an available setting for automatic reviews. You would need to adjust the review visible to date within the record. 

In order to do this in batch for multiple reviews, please contact us with the customer support number for GIFTS listed at https://www.blackbaud.com/contact-us/ which will always have the most up to date information.