In addition to Jon's suggestion: this comes from Site admin > Appearance > Navigation, where you probably have the setting 'Show my course categories' enabled. If you use this setting, combined with categories set to not be visible, you'd get the 'hidden' steps in breadcrumbs like in your screenshot.
If you don't want this to display, please uncheck the setting 'Show my course categories'. Then, your participants will just see a breadcrumb path like: Dashboard > My courses > [coursefullname].
If you don't want this to display, please uncheck the setting 'Show my course categories'. Then, your participants will just see a breadcrumb path like: Dashboard > My courses > [coursefullname].