design-themes/theme_common/views/s_separator_nav.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <template name="Got-to-Top Nav" id="s_separator_nav">
        <section class="s_separator_nav">
            <div class="container">
                <div class="row s_separator_nav_nav mini_nav_scroll">
                    <div class="s_separator_nav_item col-lg-2 float-right">
                        <a class="btn btn-success btn-xl float-right" href="#wrap" type="button">Top</a>
                    </div>
                </div>
            </div>
        </section>
    </template>
</odoo>