Closed Activities in Nav Bar - CRM 2015

Hi all -

After upgrading to CRM 2015 (on-prem), I removed the Closed Activities option from the nav bar on my main Contact form. I now want to add it back, but it no longer exists in Relationship Explorer.

I have followed the steps in this article, but it does not appear to work for 2015:

http://us.hitachi-solutions.com/2011/09/29/how-to-get-the-microsoft-crm-closed-activities-nav-bar-link-back-if-you-delete-it/

Has anyone face a similar issue? I tried using a sub-grid of Closed Activities on the form, but this only shows activities regarding.

Thanks.