Since we're going alphabetically, the last part of the funnel process is the first! So “from bottom to top.” The bottom of the funnel relates to a phase of the buying process that leads reach when they're about to close as new customers. You've identified a problem, looked around for possible solutions, and are about to make a purchase.
The next steps for leads in this phase are usually a call from a sales rep, a demo, or a free consultation — depending on what type of company is trying to close the lead.