It is often referred to as the ‘hamburger-position’, the special position between operations and (top) management, that supervisors take upon themselves.
On the one hand, managers at this level need to have enough specialized knowledge about operations. On the other, they need to be able to monitor motivations and behavior, organize operational processes and inspire their team; the team they were a part of.
They often used to work in operations themselves and now have to lead and manage the people they used to work with. This requires particular skills in leadership, motivation and management.