silverstripe-multiform/templates/Includes/MultiFormProgressList.ss

<ul class="stepIndicator current-$CurrentStep.class">
    <% loop $AllStepsLinear %>
        <li class="$ClassName<% if $LinkingMode %> $LinkingMode<% end_if %><% if $FirstLast %> $FirstLast<% end_if %><% if $ExtraClasses %> $ExtraClasses<% end_if %>">
            <% if $LinkingMode = current %>
            <% else %>
                <% if $ID %>
                    <a href="{$Top.URLSegment}/?${Top.GetVar}={$SessionID}&amp;StepID={$ID}">
                <% end_if %>
            <% end_if %>

            <% if $Title %>$Title<% else %>$ClassName<% end_if %>

            <% if $LinkingMode = current %>
            <% else %>
                <% if $ID %></a><% end_if %>
            <% end_if %>
        </li>
    <% end_loop %>
</ul>