General help

First question - how do you know where your users are? Do you have that reliably stored somewhere?

That looks like something that would require quite a few days or a small number of weeks of developer time. And to expand on Howards question, where would you expect the information to come from? One source would be the self reported country in users profiles, which is as good as or better than alternatives based on server log stuff.

These kinds of charts are easily produced with Tableau. You can connect Tableau to your Moodle database, and run whatever query you wish.  It appears to me that your example was created with Tableau.

Of course, the more you know about Tableau and SQL, the faster you can generate this chart.