Generally at a larger company with a more defined process the people that make acquisitions will be at least a piece of the corporate development team along with a product head.

It seems like a person, or group, inside the company becomes aware of a target and advocates for the acquisition of that target. The product group might then make first contact to explore the opportunity of acquisition (confirming interest) and hand off to the corp dev team to complete the transaction while keeping an eye on the whole thing.