Assuming you're using HTML5...
Try this:
<nav id="bmenu">
[[Wayfinder?
&startId=`5`
&level=`0`
&rowTpl=`rowTpl`
&innerTpl=`innerTpl`
&hideSubMenu=`0`]]
</nav>
Setting &level=`0` lets the menu show all children. If you want to limit it to 4 levels for some reason (assuming you have more than 4 levels), you can use the &level parameter to 4 but defaulting to 0 shows all levels by default.
You can style the rowTpl and innerTpl with the bmenu as an ID, and bmenu2 as the sublist class, i.e.:
nav#bmenu ul { }
nav#bmenu ul li ul.bmenu2{ }
create "rowTpl" chunk:
<!-- rowTpl -->
<li[[+wf.id]] class="[[+wf.classnames]]">
<a href="[[+wf.link]]" title="[[+wf.title]]" [[+wf.attributes]]>[[+wf.linktext]]</a>
[[+wf.wrapper]]
</li>
create "innerTpl" chunk:
<!-- innerTpl -->
<ul class="bmenu2 [[+wf.classnames]]">
[[+wf.wrapper]]
</ul>
☆ A M B ☆
☆ A M B ☆