我想这个会有帮助。

const linksCount = links.length;
const linksPerGroup = Math.ceil(linksCount / 3);

const firstGroupLinks = links.slice(0, linksPerGroup);
const secondGroupLinks = links.slice(linksPerGroup, linksPerGroup * 2);
const lastGroupLinks = links.slice(linksPerGroup * 2);

corresponding links

document.querySelector('#openFirstGroupButton').addEventListener('click', () => {
  firstGroupLinks.forEach(link => window.open(link));
});

document.querySelector('#openSecondGroupButton').addEventListener('click', () => {
  secondGroupLinks.forEach(link => window.open(link));
});

document.querySelector('#openLastGroupButton').addEventListener('click', () => {
  lastGroupLinks.forEach(link => window.open(link));
});

您可以创建链接块，告诉大小：

let links = [];//links array
let groupArr = [];
const groupSize = 3;
for (let i = 0; i < links.length; i += groupSize) {
  const chunk = links.slice(i, i + groupSize);
  groupArr.push(chunk);
}

由于链接数是整数，为什么不将其四舍五入，如：
如果你有20个链接，你把你的链接分成7-7-6？
所以你要做：

const list = [
   // whatever lists you have here
  ]; 
  const take = Math.ceil(list.length / 3);

  const firstList = links.slice(0,take);
  const secondList = links.slice(take, take*2);
  const thirdList = links.slice(take*2); // this will take until the end