Set up a trigger that calls spawn.sqf. Setup 3 markers called mygroupstart and wp1 and wp2.
Spawn.sqf contents:
_mygroup = [getmarkerPos "mygroupstart", EAST, ["O_officer_F","O_medic_F","O_engineer_F","O_Soldier_A_F","O_Soldier_lite_F","O_soldier_repair_F","O_soldier_UAV_F","O_Soldier_GL_F","O_soldier_exp_F","O_Soldier_A_F","O_medic_F","O_medic_F","O_Soldier_AR_F"],[],[],[],[],[],180] call BIS_fnc_spawnGroup;
_wp1 = _mygroup addWaypoint [getmarkerpos "wp1", 0];
_wp1 setWaypointType "MOVE";
_wp1 setWaypointSpeed "NORMAL";
_wp1 setWaypointBehaviour "AWARE";
_wp1 setWaypointFormation "LINE";
_wp2 = _mygroup addWaypoint [getmarkerpos "wp2", 0];
_wp2 setWaypointType "SAD";
_wp2 setWaypointSpeed "NORMAL";
_wp2 setWaypointBehaviour "AWARE";
_wp2 setWaypointFormation "COLUMN";
_wp3 = _mygroup addWaypoint [getmarkerpos "mygroupstart", 0];
_wp3 setWaypointType "cycle";
_wp3 setWaypointSpeed "NORMAL";
_wp3 setWaypointBehaviour "AWARE";
_wp3 setWaypointFormation "COLUMN";
Preview and move into the trigger area.