https://www.washburnlaw.edu/_files/js/accordion-tree.js

1$(document).ready(function(){
2$('#tree').treed();
3});
4$.fn.extend({
5    treed: function (o) {
6      
7      var openedClass = 'glyphicon-minus-sign';
8      var closedClass = 'glyphicon-plus-sign';
9      
10      if (typeof o != 'undefined'){
11        if (typeof o.openedClass != 'undefined'){
12        openedClass = o.openedClass;
13        }
14        if (typeof o.closedClass != 'undefined'){
15        closedClass = o.closedClass;
16        }
17      };
18      
19        //initialize each of the top levels
20        var tree = $(this);
21        tree.addClass("tree");
22        tree.find('li').has("ul").each(function () {
23            var branch = $(this); //li with children ul
24            branch.prepend("<i class='indicator glyphicon " + closedClass + "'></i>");
25            branch.addClass('branch');
26            branch.on('click', function (e) {
27                if (this == e.target) {
28                    var icon = $(this).children('i:first');
29                    icon.toggleClass(openedClass + " " + closedClass);
30                    $(this).children().children().toggle();
31                }
32            })
33            branch.children().children().toggle();
34        });
35        //fire event from the dynamically added icon
36      tree.find('.branch .indicator').each(function(){
37        $(this).on('click', function () {
38            $(this).closest('li').click();
39        });
40      });
41        //fire event to open branch if the li contains an anchor instead of text
42        tree.find('.branch>a').each(function () {
43            $(this).on('click', function (e) {
44                $(this).closest('li').click();
45                e.preventDefault();
46            });
47        });
48        //fire event to open branch if the li contains a button instead of text
49        tree.find('.branch>button').each(function () {
50            $(this).on('click', function (e) {
51                $(this).closest('li').click();
52                e.preventDefault();
53            });
54        });
55    }
56});