Get two array from array of objects
I'm not sure this is any simpler but it does use only a single loop:

 const dataset={ ... }
 const names=[], countries=[]
 for (var d of dataset) { 
     names.push(d.name); 
     countries.push(d.country);
 }


Surprisingly, according to jsben.ch, this approach is about 6 times faster than running map twice.