¿Cómo creo una consulta SQL para tener valores MTD y YTD en la misma fila?

Tengo un Crystal Report que estoy convirtiendo a SSRS actualmente. Este informe tiene 3 columnas para MTD (valores del mes hasta la fecha) y 3 columnas para YTD (valores del año hasta la fecha). Puedo separar esas 3 columnas, pero para la precisión de los datos necesito combinarlas en una declaración SQL para generar en una fila. Pude acercarlo casi usando algunas funciones de fusión en SQL. El problema es que no me deja usar los comandos agrupar por y me arroja un error. ¿Qué debo editar en mi consulta SQL de la forma que se muestra en el siguiente Crystal Report?
Error :

Msg 512, Level 16, State 1, Line 106
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

Crystal Report actual que estoy convirtiendo a SSRS

EDITAR: Acabo de crear un dbfiddle de muestra: DB Fiddle – Zona de juegos de bases de datos SQL[^]

En el Código 2 he intentado usar algunas uniones con y pero me está dando algún error como

Incorrect syntax near the keyword 'with'. If this statement is a common table expression, an xmlnamespaces clause or a change tracking context clause, the previous statement must be terminated with a semicolon.

Lo que he probado:

Código 1

SET ARITHABORT OFF
SET ANSI_WARNINGS OFF
SELECT coalesce((Select ((SUM( "IS_vwSalesbyProductLineComp"."sls_amt")-SUM( "IS_vwSalesbyProductLineComp"."cost_amt"))/SUM( "IS_vwSalesbyProductLineComp"."sls_amt"))*100 ),0) AS G1MTD,
	   "IS_vwSalesbyProductLineComp"."Mainslspsn_name",
	   "IS_vwSalesbyProductLineComp"."PCSummarized",
	   coalesce ((SELECT SUM("IS_vwSalesbyProductLineComp"."qty_to_ship"-"IS_vwSalesbyProductLineComp"."qty_return_to_stk")FROM "100"."dbo"."IS_vwSalesbyProductLineComp"
   where Year = 2021
   and Month between 1 and 12 Group by Mainslspsn_name,PCSummarized),0) AS Qty_Sold,
	   coalesce ((SELECT SUM("IS_vwSalesbyProductLineComp"."sls_amt")FROM "100"."dbo"."IS_vwSalesbyProductLineComp"
   where Year = 2021
   and Month between 1 and 12 Group by Mainslspsn_name,PCSummarized),0) AS YTD_Sales,
	   coalesce ((SELECT SUM("IS_vwSalesbyProductLineComp"."cost_amt")FROM "100"."dbo"."IS_vwSalesbyProductLineComp"
   where Year = 2021
   and Month between 1 and 12 Group by Mainslspsn_name,PCSummarized),0) AS YTD_COGS,
	   coalesce((Select ((SUM( "IS_vwSalesbyProductLineComp"."sls_amt")-SUM( "IS_vwSalesbyProductLineComp"."cost_amt"))/SUM( "IS_vwSalesbyProductLineComp"."sls_amt"))*100 
	   FROM "100"."dbo"."IS_vwSalesbyProductLineComp"
   where Year = 2021
   and Month between 1 and 12 Group by Mainslspsn_name,PCSummarized),0) AS G2YTD,
		SUM("IS_vwSalesbyProductLineComp"."qty_to_ship"-"IS_vwSalesbyProductLineComp"."qty_return_to_stk") 
		AS Qty_Sold,
   		SUM("IS_vwSalesbyProductLineComp"."sls_amt") 
		AS MTD_Sales,
      	SUM("IS_vwSalesbyProductLineComp"."cost_amt") 
		AS MTD_COGS   
   FROM "100"."dbo"."IS_vwSalesbyProductLineComp"
   where Year = 2021
   and Month = 12
   Group by Mainslspsn_name,PCSummarized
   order by PCSummarized

Código 2

SET ARITHABORT OFF
SET ANSI_WARNINGS OFF
WITH 
T1 AS
(
SELECT (
       SELECT((SUM(IS_vwSalesbyProductLineComp.sls_amt) - SUM(IS_vwSalesbyProductLineComp.cost_amt)) / SUM(IS_vwSalesbyProductLineComp.sls_amt)) * 100) AS G1MTD, 
       IS_vwSalesbyProductLineComp.Mainslspsn_name, 
       IS_vwSalesbyProductLineComp.PCSummarized, 
       (
       SELECT SUM(IS_vwSalesbyProductLineComp.qty_to_ship - IS_vwSalesbyProductLineComp.qty_return_to_stk)
       FROM "100".dbo.IS_vwSalesbyProductLineComp
       WHERE Year = 2021
             AND Month BETWEEN 1 AND 12
       GROUP BY Mainslspsn_name, 
                PCSummarized) AS Qty_Sold, 
       (
       SELECT SUM(IS_vwSalesbyProductLineComp.sls_amt)
       FROM "100".dbo.IS_vwSalesbyProductLineComp
       WHERE Year = 2021
             AND Month BETWEEN 1 AND 12
       GROUP BY Mainslspsn_name, 
                PCSummarized) AS YTD_Sales, 
      (
       SELECT SUM(IS_vwSalesbyProductLineComp.cost_amt)
       FROM "100".dbo.IS_vwSalesbyProductLineComp
       WHERE Year = 2021
             AND Month BETWEEN 1 AND 12
       GROUP BY Mainslspsn_name, 
                PCSummarized) AS YTD_COGS, 
       (
       SELECT((SUM(IS_vwSalesbyProductLineComp.sls_amt) - SUM(IS_vwSalesbyProductLineComp.cost_amt)) / SUM(IS_vwSalesbyProductLineComp.sls_amt)) * 100
       FROM "100".dbo.IS_vwSalesbyProductLineComp
       WHERE Year = 2021
             AND Month BETWEEN 1 AND 12
       GROUP BY Mainslspsn_name, 
                PCSummarized) AS G2YTD, 
       SUM(IS_vwSalesbyProductLineComp.qty_to_ship - IS_vwSalesbyProductLineComp.qty_return_to_stk) AS Qty_Sold2, --> renamed because ambigous
       SUM(IS_vwSalesbyProductLineComp.sls_amt) AS MTD_Sales, 
       SUM(IS_vwSalesbyProductLineComp.cost_amt) AS MTD_COGS
FROM "100".dbo.IS_vwSalesbyProductLineComp
WHERE Year = 2021
      AND Month = 12
GROUP BY Mainslspsn_name, 
         PCSummarized
),
T2 AS 
(
SELECT 0 AS C1, '' AS C2, '' AS C3, 0 AS C4, 0 AS C5, 0 AS C6, 0 AS C7, 0 AS C8, 0 AS C9, 0 AS C10
),
T3 AS
(
SELECT * FROM T1
UNION 
SELECT * FROM T2
)
SELECT SUM(G1MTD) AS G1MTD, 
   (SELECT [text()] = Mainslspsn_name
       FROM "100".dbo.IS_vwSalesbyProductLineComp 
       FOR XML 
           PATH(''),
           TYPE
   ).value
     (
         './text()[1]', 
         'nvarchar(max)'
     ),
   (SELECT [text()] = PCSummarized
       FROM "100".dbo.IS_vwSalesbyProductLineComp 
       FOR XML 
           PATH(''),
           TYPE
   ).value
     (
         './text()[1]', 
         'nvarchar(max)'
     ),
       SUM(Qty_Sold) AS Qty_Sold,
       SUM(YTD_Sales) AS YTD_Sales,
       SUM(YTD_COGS) AS YTD_COGS,
       SUM(G2YTD) AS G2YTD,
       SUM(Qty_Sold2) AS Qty_Sold2,
       SUM(MTD_Sales) AS MTD_Sales,
       SUM(MTD_COGS) AS MTD_COGS
FROM T3
GROUP BY Mainslspsn_name, 
         PCSummarized
ORDER BY PCSummarized;