<p>{% assign series_pages = site.tags.series_acme %}

{% for p in pages %}
{% if p.series == "Getting Started" %}
{% assign nextTopic = page.weight | plus: "1"  %}
{% if p.weight == nextTopic  %}
<a href="{{p.url | remove: "/"}}"><button type="button" class="btn btn-primary">Next: {{p.title}}</button></a>
{% endif %}
{% endif %}
{% endfor %}

</p>