JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Open the console</h1>

JavaScript

var data = [
      [
       {name:"John", age:32, x:false}, 
       {name:"Mark", age:44, x:false}, 
       {name:"John", age:21, x:true}
      ],

      [
       {name:"John", age:65, x:false}, 
       {name:"Mark", age:77, x:false}, 
       {name:"John", age:78, x:true}
      ],

      [
       {name:"John", age:11, x:false}, 
       {name:"Mark", age:15, x:false}, 
       {name:"John", age:65, x:true}
      ]
    ];


console.log(data);

function compare(a,b) {
  if (b.x)
     return 1;
  if (a.x)
    return -1;
  return 0;
}

for(var i=0,l=data.length; i<l; i++) data[i].sort(compare);

console.log(data);