Chrome DevTools Console Hack to list all Data Attributes in table view. Credits to: https://www.thyngster.com/tip-quickly-debugqa-data-attributes/
For GTM I assume. [updated June 28, 2017]
(function() {
var elements = [].slice.call(document.querySelectorAll('*')).filter(function(el) {
if (typeof (el.dataset) != "undefined")
return Object.keys(el.dataset).length != 0;
});
var data = [];
var i = elements.length;
while (i--) {
var el = JSON.parse(JSON.stringify(elements[i].dataset));
data.push(el);
el["_element_type"] = elements[i].nodeName;
}
console.table(data);
})();