The design seat, across every segment above
Worth stating as its own group, because it is the one nobody maps. The engineer who chooses the part is rarely the person who buys it, and often sits at a different site under a different address. No public register records who designs where, so this group is identified by name rather than filtered from a list, and that is exactly why it stays open.
Who signs: component engineer, hardware design lead, sustaining engineering manager, obsolescence engineer.