JSFiddle - React, Tailwind, and code Playground
HTML
<div id="result"></div>
JavaScript
var string = ["test_data/new_directory/ok.txt","test_data/reads_1.fq","test_data/test_ref.fa"];
var foldersJSON, foldersArray;
$(string).each(function(){
console.log(this.split("/"));
a = this.split("/");
for (i = 0; i < a.length; i++)
foldersArray[a[i]] = foldersArray[a[i+1]];
});