SQL Server 2019

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CREATE TABLE YourTable (
  "CustomerNumber" INTEGER,
  "Company" VARCHAR(6),
  "Year" INTEGER,
  "WeekNumber" INTEGER,
  "OrderDate" date,
  "OrderDayName" VARCHAR(9),
  "LeadDays" INTEGER,
  "DeliveryDate" date,
  "DeliveryDayName" VARCHAR(9)
);

INSERT INTO YourTable
  ("CustomerNumber", "Company", "Year", "WeekNumber", "OrderDate", "OrderDayName", "LeadDays", "DeliveryDate", "DeliveryDayName")
VALUES
  ('5002', 'Comp_A', '2022', '15', '2022-04-03', 'Sunday', '1', '2022-04-04', 'Monday'),
  ('5002', 'Comp_A', '2022', '15', '2022-04-04', 'Monday', '1', '2022-04-05', 'Tuesday'),
  ('5002', 'Comp_A', '2022', '15', '2022-04-05', 'Tuesday', '1', '2022-04-06', 'Wednesday'),
  ('5002', 'Comp_A', '2022', '15', '2022-04-06', 'Wednesday', '1', '2022-04-07', 'Thursday'),
  ('5002', 'Comp_A', '2022', '15', '2022-04-07', 'Thursday', '1', '2022-04-08', 'Friday'),
  ('5002', 'Comp_A', '2022', '15', '2022-04-08', 'Friday', '1', '2022-04-09', 'Saturday'),
  ('5002', 'Comp_A', '2022', '15', '2022-04-09', 'Saturday', '1', '2022-04-10', 'Sunday'),
  ('310365', 'Comp_A', '2022', '15', '2022-04-05', 'Tuesday', '1', '2022-04-06', 'Wednesday'),
  ('310365', 'Comp_A', '2022', '15', '2022-04-07', 'Thursday', '1', '2022-04-08', 'Friday'),
  ('310428', 'Comp_A', '2022', '15', '2022-04-06', 'Wednesday', '1', '2022-04-07', 'Thursday'),
  ('19401', 'Comp_B', '2022', '15', '2022-04-04', 'Monday', '1', '2022-04-05', 'Tuesday'),
  ('19401', 'Comp_B', '2022', '15', '2022-04-05', 'Tuesday', '1', '2022-04-06', 'Wednesday'),
  ('19401', 'Comp_B', '2022', '15', '2022-04-06', 'Wednesday', '1', '2022-04-07', 'Thursday'),
  ('19401', 'Comp_B', '2022', '15', '2022-04-07', 'Thursday', '1', '2022-04-08', 'Friday'),
  ('19401', 'Comp_B', '2022', '15', '2022-04-08', 'Friday', '1', '2022-04-09', 'Saturday');

15 rows affected

SELECT
  CustomerNumber,
  Company,
  Year,
  WeekNumber,
  MAX(CASE WHEN rn = 1 THEN LeadDays     END)     LeadDays_1,
  MAX(CASE WHEN rn = 1 THEN OrderDate    END)    OrderDate_1,
  MAX(CASE WHEN rn = 1 THEN DeliveryDate END) DeliveryDate_1,
  MAX(CASE WHEN rn = 2 THEN LeadDays     END)     LeadDays_2,
  MAX(CASE WHEN rn = 2 THEN OrderDate    END)    OrderDate_2,
  MAX(CASE WHEN rn = 2 THEN DeliveryDate END) DeliveryDate_2,
  MAX(CASE WHEN rn = 3 THEN LeadDays     END)     LeadDays_3,
  MAX(CASE WHEN rn = 3 THEN OrderDate    END)    OrderDate_3,
  MAX(CASE WHEN rn = 3 THEN DeliveryDate END) DeliveryDate_3,
  MAX(CASE WHEN rn = 4 THEN LeadDays     END)     LeadDays_4,
  MAX(CASE WHEN rn = 4 THEN OrderDate    END)    OrderDate_4,
  MAX(CASE WHEN rn = 4 THEN DeliveryDate END) DeliveryDate_4,
  MAX(CASE WHEN rn = 5 THEN LeadDays     END)     LeadDays_5,
  MAX(CASE WHEN rn = 5 THEN OrderDate    END)    OrderDate_5,
  MAX(CASE WHEN rn = 5 THEN DeliveryDate END) DeliveryDate_6
FROM (
    SELECT *,
      rn = ROW_NUMBER() OVER (
          PARTITION BY CustomerNumber, Company, Year, WeekNumber
          ORDER BY OrderDate, DeliveryDate)
    FROM YourTable t
) t
GROUP BY
  CustomerNumber,
  Company,
  Year,
  WeekNumber;

CustomerNumber	Company	Year	WeekNumber	LeadDays_1	OrderDate_1	DeliveryDate_1	LeadDays_2	OrderDate_2	DeliveryDate_2	LeadDays_3	OrderDate_3	DeliveryDate_3	LeadDays_4	OrderDate_4	DeliveryDate_4	LeadDays_5	OrderDate_5	DeliveryDate_6
5002	Comp_A	2022	15	1	2022-04-03	2022-04-04	1	2022-04-04	2022-04-05	1	2022-04-05	2022-04-06	1	2022-04-06	2022-04-07	1	2022-04-07	2022-04-08
19401	Comp_B	2022	15	1	2022-04-04	2022-04-05	1	2022-04-05	2022-04-06	1	2022-04-06	2022-04-07	1	2022-04-07	2022-04-08	1	2022-04-08	2022-04-09
310365	Comp_A	2022	15	1	2022-04-05	2022-04-06	1	2022-04-07	2022-04-08	null	null	null	null	null	null	null	null	null
310428	Comp_A	2022	15	1	2022-04-06	2022-04-07	null	null	null	null	null	null	null	null	null	null	null	null

Warning: Null value is eliminated by an aggregate or other SET operation.