Start editor, create player unit, place ORBAT module, save mission.
Edit description.ext to add a section:
class CfgORBAT
{
class 1Sec
{
id = 1;
idType = 0;
side = "West";
size = "Section";
type = "Infantry";
commander = "L3TUC3";
commanderRank = "Colonel";
text = "%1 %2 %3";
textShort = "%1 %2 %3";
};
};
Add to CfgORBAT path and Ceiling: missionconfigfile >> "CfgOrbat" >> "1Sec"
Preview mission and note that the orbat icon and orbat viewer mentions a fireteam instead of a section.