Approval process based on variables

I am new to WebHelpDesk. I'm using this to track legal department requests.

When a client submits a ticket, I have a Change Advisory Board set up to receive notice and give their approval. For some tickets, I would like additional people to receive and approve based on variables.

Example -- does this deal include XXX? yes/no. When the client selects Yes, I would like the 2nd approval process to run with a new set of approvers.

I've set up custom fields to capture the yes/no variable.

What's the best/easiest way to accomplish this?

Thanks