To add a custom tab to Daily Reports in the portal, first go to Project Management in Viewpoint > Programs > PM Daily Logs > right click the form (don't click into any fields) > go to the tab: Tab Pages > then click add.
Name your tab and then click OK.
Once you have added the tab, you will need to add a custom field to it. Please see the article: How to add ud fields to your Daily Report
Then, go to Admin > Portal Settings > Daily Reports > and make sure you list your tab name in this setting.
Then, go to Admin > Portal Settings > and click the Refresh Synonyms button. Once this process has been concluded, logout and log back in. You should see your new custom tab showing up in the Daily Reports in the portal.