XF 2.0 widget_members_online

[Itworx4me]

I only want to have certain usergroups show up in the members online. What do i need to change in this line of code to make this happen?

<xf:foreach loop="$online.users" value="$user"><xf:trim>
                            <li><xf:username user="$user" rich="true" class="{{ !$user.visible ? 'username--invisible' : '' }}" /></li>
                        </xf:trim></xf:foreach>

Thanks,
Itworx4me