In Constellation UI, the list of pages exposed in the left navigation of the work portal are automatically generated from your portal channel. You can configure the pages, assign the icons as well as configure the page visibility:

Sometimes, you want to extend the navigation with links that are outside of your current application. For example, you want to point to an external help page or a search page that could be on a different URL or different domain.

It is possible to extend the default behavior and add some additional pages to the navigation. Note that these pages will always be added after the auto-generated pages. Here is an example of adding an extra 'help' navigation item that could point to another web site:

In order to implement this functionality, resave the data transform called 'pyPopulateAdditionalNavPages' into your application layer. The DT will be called when the data page D_pyAdditionalNavPages is loaded during the DX API /portals/{PortalID} call. The content of the data page will be added to the auto-generated list of pages.

You can add different pages based on portal name or user privileges / access group - The name of the icon must be preceded by "pi pi-" and must be a valid icon name in the Constellation Component Library. For more information on out-of-the-box Constellation icons, see Icon reference. 

This is also a good approach when extendubg the default Constellation functionality and exposing some features and functionality that are only offered in Traditional UI. For example:

• Delegated rules - see article https://docs.pega.com/bundle/platform/page/platform/app-dev/delegating-rules-data-type-2.html
• Specific harnesses (like User Profile, Documents, Spaces, Report Browse) - see https://docs.pega.com/bundle/platform/page/platform/user-experience/launching-traditional-from-constellation.html

To achieve this functionality, you will need a separate application rule with a different url alias. Your traditional application could be a built-on of your Constellation application. The users need to have access to the access groups of the 2 applications.