The ICS title of director is applied to the supervisor of a:

The ICS (Incident Command System) title of director is specifically used for the supervisor of a branch. In the organizational structure of ICS, branches are established to manage a specific segment of the overall incident, often when the complexity of an incident requires further division beyond divisions or sections. The branch director is responsible for overseeing multiple divisions or groups that fall within their branch. This hierarchical structure allows for effective management and coordination during complex incidents, ensuring that resources are utilized efficiently and that communication flows clearly between various teams.

The other organizational levels, such as divisions, sections, and companies, are tied to different titles and responsibilities within the ICS framework. For example, a division supervisor oversees a specific geographic area or functional aspect, while a section is managed by a section chief who may oversee multiple branches. Therefore, the use of the title "director" is appropriately designated for those who oversee branches in the ICS hierarchy.