Hi Eason
The global search engine SOLR does work with Totara - configuring this on the web server is tricky and this does have some limitations including not searching courses not having enrolment records. The global search is more suitable for searching the content in activities such as text , pdf , or word files
If you are wanting to search courses through key words then we recommend the course catalogue allows full text searches this and allows searches by tags, course description content and course metadata to help locate the relevant course.
regards