<!-- language-all:lang-sql -->
#Formatting#
You use a mixture of `lowercase` and `UPPERCASE` keywords, you should stick to one or the other. It makes it much easier to read the query if you do. I am going to stick with `UPPERCASE` as it is the convention.

#An alternate approach#
Might I suggest storing the minimum `SortSequence` value in a variable and then using that to filter out records you don't need.

Here is what I came up with.

    DECLARE @Minimum_Sort_Seq INT = 
    (
    	SELECT MIN(SortSequence)
    	FROM WebcastChannelWebcastEventLink
    )
    
    SELECT wcwel.WebcastChannelId,wcwel.WebcastEventId
    FROM WebcastChannelWebcastEventLink wcwel
    WHERE wcwel.SortSequence = @Minimum_Sort_Seq

This query returned the same results in my testing. You can run this to check yourself:

    CREATE TABLE #WebcastChannelWebcastEventLink
	(
		WebcastChannelId INT,
		WebcastEventId INT,
		SortSequence INT
	) 

	INSERT INTO #WebcastChannelWebcastEventLink
	SELECT 1,2,1 UNION ALL
	SELECT 1,5,2 UNION ALL
	SELECT 1,3,3 UNION ALL
	SELECT 2,7,2 UNION ALL
	SELECT 2,8,1

	SELECT wcwel.WebcastChannelId, wcwel.WebcastEventId
	FROM #WebcastChannelWebcastEventLink wcwel WITH (NOLOCK)
	INNER JOIN #WebcastChannelWebcastEventLink wcwel1 WITH (NOLOCK) 
		ON wcwel1.WebcastChannelId = wcwel.WebcastChannelId
	GROUP BY
	wcwel.WebcastChannelId,
	wcwel.WebcastEventId,
	wcwel.SortSequence
	HAVING
	wcwel.SortSequence = MIN(wcwel1.SortSequence)

	DECLARE @Minimum_Sort_Seq INT = 
	(
		SELECT MIN(SortSequence)
		FROM WebcastChannelWebcastEventLink
	)

	SELECT wcwel.WebcastChannelId,wcwel.WebcastEventId
	FROM WebcastChannelWebcastEventLink wcwel
	WHERE wcwel.SortSequence = @Minimum_Sort_Seq

	DROP TABLE #WebcastChannelWebcastEventLink