;WITH
			cteGetNewVSOldGroup (oldGroupId, newGroupId)
			AS
			(
				select t1.oldGroupId,t2.id from #tblGroups t1 Inner join 
				[DB1].[dbo].Dyn_Group t2 on t1.name=t2.name
				where t2.CompanyRef=@newCompanyRef and t2.UserRef=@newUserId
			)
		INSERT INTO [DB1].[dbo].[Dyn_Group2]
           ([GrandParent]
           ,[Parent]
           ,[Child])
		select t2.newGroupId,t3.newGroupId,t4.newGroupId from #tblGroup2Group t1
		inner join cteGetNewVSOldGroup as t2 on t1.GrandParent=t2.oldGroupId
		inner join cteGetNewVSOldGroup as t3 on t1.Parent=t3.oldGroupId
		inner join cteGetNewVSOldGroup as t4 on t1.Child=t4.oldGroupId

CREATE DATABASE DB1
CREATE DATABASE DB2
GO

USE DB1
GO

CREATE TABLE dbo.TableInDB1(
	col1 CHAR(1)
)
GO

INSERT dbo.TableInDB1 VALUES ('1')
GO

--==== Switch to another context
USE DB2
GO

;WITH cteTest (col1) AS
(
	SELECT 
		col1
	FROM 
		DB1.dbo.TableInDB1
			
)
SELECT
	*
FROM
	cteTest