YouTube insights are used to track from where traffic comes to your videos. It is possible that you can change the region by clicking on the map but locating a particular country is difficult as the size is small.
So If you want to change the country rather quickly just click on the which should be saying “All” for the Selected region. This will immediately change into a text box where you can type in the country name and it will show you the list as you type. Enjoy!