Good day everyone, I don't know if there's an answer to this question already on this forum but I haven't come across it that's why I'm asking.
How can a Computer Based Testing platform like http://www.cbt.uniport.edu.ng be set up using moodle?
I don't really understand the question. That site is Moodle. You install Moodle on a server. Then on configure it the way you want.
I assume you have a more specific question that that, but you will have to say what it is.
I second Tims comment, you have (nearly) given the URL of a site running Moodle. What features are you interested in. You need to be specific in your question.