Is there a way to build up a multiple step sequential approval process with the collaboration bundle for the TM 5.0.3+composer?
There seems to be in-built in the system a 1-step and 2-step review and I'm wondering whether this could be customized for further steps (even with branching conditions).
Are there sampes/examples I can download also?
Yes, you can, and yes there are.
Please see the Avoka Transact Product Documentation
(Under the "Collaboration Jobs" section).
There, you will find examples.
This is a very advanced form of customisation, and my advice would be to seek some mentoring services from Avoka via your account manager.