nestablejs/docs/assets/js/toggle.js

NestableJS is a javascript library for creating drag & drop heirarchical lists.

const expand = document.getElementById("expand");
const collapse = document.getElementById("collapse");

const instance = new Nestable("#myList");

expand.addEventListener("click", e => {
	instance.expandAll();
});

collapse.addEventListener("click", e => {
	instance.collapseAll();
});