{{ knp_menu_render(admin.sidemenu(action), {'currentClass' : 'active'}, 'list') }}
<p>
    <div class="btn-group">
        <a type="button" class="btn {% if mode == 'list' %}btn-info active{% else %}btn-default{% endif %}" href="{{ admin.generateUrl('list', { 'filter': { 'context': { 'value': current_category is defined ? current_category.context.id|default('') : '' }}}) }}">
            <i class="fa fa-list"></i> {{ 'classification.list_mode'|trans({}, 'SonataClassificationBundle') }}
        </a>
        <a type="button" class="btn {% if mode == 'tree' %}btn-info active{% else %}btn-default{% endif %}" href="{{ admin.generateUrl('tree') }}">
            <i class="fa fa-sitemap"></i> {{ 'classification.tree_mode'|trans({}, 'SonataClassificationBundle') }}
        </a>
    </div>
</p>

{{ knp_menu_render(admin.sidemenu(action), {'currentClass' : 'active'}, 'list') }}
<div class="btn-group">
    <a type="button" class="navbar-btn btn {% if mode == 'list' %}btn-info active{% else %}btn-default{% endif %}" href="{{ admin.generateUrl('list', { 'filter': { 'context': { 'value': current_category is defined ? current_category.context.id|default('') : '' }}}) }}">
        <i class="fa fa-list"></i> {{ 'classification.list_mode'|trans({}, 'SonataClassificationBundle') }}
    </a>
    <a type="button" class="navbar-btn btn {% if mode == 'tree' %}btn-info active{% else %}btn-default{% endif %}" href="{{ admin.generateUrl('tree') }}">
        <i class="fa fa-sitemap"></i> {{ 'classification.tree_mode'|trans({}, 'SonataClassificationBundle') }}
    </a>
</div>

Fix vertical centering of buttons within a navbar in list/tree selector
Fix vertical centering of buttons within a navbar in list/tree selector

replace DIV in P which was not HTML compliant by adding .navbar-btn class
