How can we call course custom fields?

Hi all,

Can any refer any relevant API function to retrieve course custom fields.

I search the most relevant one is core_course_get_courses_by_field but it difficult to search in custom fields, showing invalid parameter error, can someone rectify the issue in below URL.

http://localhost/ms/webservice/rest/server.php?wstoken=c2fc68ac3edca08asdf16a80a7823cbf&wsfunction=core_course_get_courses_by_field&field=customfields[global_terms]&value=1   

Thanks. 

Azmat