Hi Adam Ruth,
Thank you for contacting us.
You cannot use Sitefinity Breadcrumb
control in such scenario as it is a site navigation control that reflects data provided by the SiteMap.
To achieve the required functionality you need to create your own control using the Forum API. For more information please refer to the following topics of our Developer Manual:
ForumManager Class Methods
Forums API Walkthrough
Hope this helps.
All the best,
the Telerik team
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