Запишите новое значение в атрибут data:
document.getElementById('storepoint-container').dataset.tags = 'some new value'
Вы должны сделать это в вашей функции openGroup
(я сделал это в конце, прокомментировалвсе, что не сработало):
function openGroup(evt, groupName) {
var i, groupcontent, groupboxes;
// not working:
// groupcontent = document.getElementsByClassName("groupcontent");
// for (i = 0; i < groupcontent.length; i++) {
// groupcontent[i].style.display = "none";
// }
groupboxes = document.getElementsByClassName("groupboxes");
for (i = 0; i < groupboxes.length; i++) {
groupboxes[i].className = groupboxes[i].className.replace(" active", "");
}
//not working: document.getElementById(groupName).style.display = "block";
evt.currentTarget.className += " active";
// this is the relevant part:
var storepointContainer = document.getElementById('storepoint-container');
if (groupName === 'spouse-men-content') {
storepointContainer.dataset.tags = 'hope-for-men';
} else {
storepointContainer.dataset.tags = 'betrayal & beyond';
}
}
<div class="spouse-men-box eight columns alpha center">
<div class="groupboxes" onclick="openGroup(event, 'spouse-men-content')">
<h3 class="mB25 white">Healing for Men</h3>
</div>
</div>
<div class="spouse-women-box eight columns omega center">
<div class="groupboxes" onclick="openGroup(event, 'spouse-women-content')">
<h3 class="mB25 white">Healing for Women</h3>
</div>
</div>
<div id="storepoint-container" data-tags="hope for men" data-map-id="158752ddce0df0"></div>