General developer forum

 // Course name, if appropriate.
 if (isset($COURSE) && $COURSE->id != SITEID) {

add:

// ou-specific begins
 if ($CFG->ousite=='OCI') {
 // Make the breadcrumb include the category/subcategory path
 require_once( $CFG->dirroot.'/local/ocilib.php' );

 // Get the category path.
 $category_path = oci_category_path( $COURSE->category );

 // Put in the All Topics link
 $strcategories = get_string('allcategories');
 $navlinks[] = array('name' => $strcategories,
 'link' => $CFG->wwwroot.'/course/index.php',
 'type' => 'misc');

 // Put in each of the category links
 foreach( $category_path as $cat_id => $cat_name ) {
 $navlinks[] = array('name' => $cat_name,
 'link' => $CFG->wwwroot.'/course/category.php?id='.$cat_id,
 'type' => 'misc');
 }
 }
// ou-specific ends

it uses the following function:

 /**
 * get the category as a path (e.g., tom/dick/harry)
 * @param int id the id of the most nested catgory
 * @param string delimiter the delimiter you want
 * @return string the path
 */
 function oci_category_path( $parentid ) {
 $path = '';
 do {
 if (!$category = get_record( 'course_categories','id',$parentid )) {
 print_error( "Error reading category record - $parentid" );
 }
 $name = $category->name;
 $parentid = $category->parent;
 $id = $category->id;
 if (!empty($path)) {
 $path = "$id|{$name}-{$path}";
 }
 else {
 $path = "$id|{$name}";
 }
 } while ($parentid != 0);

 // Now split the path back down and create an array to hold the
 // category/subcategory structure

 $temp_categories = explode( '-', $path );

 foreach( $temp_categories as $cat ) {
 list( $cat_id, $cat_name ) = explode( '|', $cat );
 $categories[$cat_id] = $cat_name;
 }

 return $categories;
 }

Of course, you may want to tweak this to meet exactly your requirements.