cv.js

var items = this.context.binding.get('value').items,
    html = '<table class="table table-sm table-bordered"><thead class="thead-default"><tr><th>Property</th><th>Value</th></tr></thead>';

html += items.map(function (i) {
    var a;
    try {
        a = JSON.parse(i.value);
    } catch (e) {
        a = i.value;
    }
    
    return '<tr>' +
        '<th>' + i.name + '</th>' +
        '<td style="white-space: pre;">' + JSON.stringify(a, null, 4) + '</td>' +
        '</tr>'
}).join('') + '</table>';

this.context.element.innerHTML = html;

prescript.js

var d = tw.system.currentProcessInstance.businessData;

var m = []

d.keyArray().sort().forEach(function (k) {
	if (k === 'vars') return;

	var val = d.get(k);
	var v = (typeof val !== 'object') ? val : JSON.stringify(BPMJSON.convertTwToJS(val));
	v = String(v);
	
	m.push({ name: k, value: v });
});

tw.local.vars = m