Two levels of approval of leave request without using workflow

Hi Experts,

it is possible to achieve two levels of approvals of leave request without using workflow? I read a lot of discussion on SCN, but a lot of topics concered using workflow template.

If not, so what's I need to do in case of using workflow to achieve two levels of approvals of leave request? Copy standard workflow template WS21500001 and customize it? What's more, do I need enhance class CL_PT_REQ_WF_ATTRIBS about two methods: reset status to 'sent' and set the next processor?

Can You explain me and help me?

Thanks in advance

Marcin