The course category filter is not enabled by default in the Edjet LMS portal.
Steps to add the course categories filter:
'tpl' => 'webparts/courses/courses_categories_dropdown.tpl.php', 'type' => iWebPart::LIST_TYPE_CATEGORIES, 'num_rows' => 0
Check that the settings are correct by switching to the User portal by clicking View portal.
To remove the course categories, repeat the procedure, removing the [COURSES] webpart with the "courses_categories_dropdown.tpl.php" property.