The only way to access the fieldsets when using Template Toolkit is to
walk the raw _form object. Most other form attributes are much easier
to access. I have attached a patch that allows the user to access the
fieldsets in the same way they would the fields, i.e. via an array,
fieldsets, or via a hash, fieldset.
[% FOREACH fieldset = formbuilder.fieldsets %]
<fieldset>
<legend>[% fieldset.label %]</legend>
do stuff.
</fieldset>
[% END %]
or for a fieldset named 'general_info'
[% formbuilder.fieldset.general_info.label %]