I am looking for a widget that has drop down tree similar to the layer list. I am wanting to modify it to set links to metadata for my arcmap project I am displaying in web app viewer. I am not very good at writing code, but can modify code...
The enhanced Bookmark widget may be a good starting point then:
Enhanced Bookmark Widget Version 2.5 - 08/17/17
There are quite a few free open source. have you ever looked at jstree? it is simple to plug in dealing with JSON data. It will look at this:
You can customize easily by change font, icons etc.
Retrieving data ...