JSFiddle - React, Tailwind, and code Playground

JavaScript

var video1 = document.getElementById('video1');
var video2 = document.getElementById('video2');

video1control.addEventListener('mousemove', function() {
  video1.currentTime = event.x;
  video2.currentTime = event.x;
})

video2control.addEventListener('mousemove', function(event) {
  video1.currentTime = event.x;
  video2.currentTime = event.x;
})