JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/handlebars.js/2.0.0-beta.1/handlebars.min.js"></script>
<script id="template" type="text/x-template">
<table>
    {{#each privileged_users}}
        {{! using a block helper to print the details, first parameter is the context object and second parameter is key }}
        {{#printUserDetails ../users this}}
            <tr><td>{{title}} {{name}}</td></tr>
        {{else}}
            <tr><td>{{this}} details not available</td></tr>
        {{/printUserDetails}}
    {{/each}}
</table>
</script>

<div id="results"></div>

JavaScript

var data = {
  privileged_users: [ "user1", "user2", "user4" ],
  users: {
      user1: { name: "N1", title: "Mr." },
    user2: { name: "N2" },
    user3: { name: "N3" }
  }
};

Handlebars.registerHelper("printUserDetails", function(usersObj, currUser, options) {
    if (usersObj && currUser) {
        var context = usersObj[currUser];
        if (context) {
            // options contain the block as compiled function in "fn"
            return options.fn(context);
        }
    }
    // Printing the name of user in else
    return options.inverse(currUser);
});

var template = Handlebars.compile(document.getElementById('template').innerHTML);

document.getElementById('results').innerHTML = template(data);