Get SQL XML element using variable

If I have a column that is like 11.22.33.44.55, I am trying to get one of the values depending on what level the user is asking for. So I have a variable for level. This is what I am using as my starting point:

DECLARE @ProjectID int,
		@Level int
SET @ProjectID = 58
SET @Level = 2

SELECT 				 
	CAST('<t>' + REPLACE(ParentId1 , '.','</t><t>') + '</t>' AS XML).value('/t[1]','varchar(50)')
FROM 
	@tmptbl
WHERE
	linked_task = @ProjectID

So this works (would return 11), but where I have /t[1], I want to use @Level instead of [1], so that if the supplied level is 2, it will return '22', if it is 3, would return '33', and so on, so I tried the follow

Tried:

CAST('<t>' + REPLACE(ParentId1 , '.','</t><t>') + '</t>' AS XML).value('/t['+@Level+']','varchar(50)')

Get this error:

> The argument 1 of the XML data type method "value" must be a string literal.

Tried:

CAST('<t>' + REPLACE(ParentId1 , '.','</t><t>') + '</t>' AS XML).value('/t["@Level"]','varchar(50)')

Get this error:

> XQuery [value()]: Only 'h ttp://www.w3.org/2001/XMLSchema#decimal?', 'h ttp://www.w3.org/2001/XMLSchema#boolean?' or 'node()*' expressions allowed as predicates, found 'xs:string'

How do I accomplish this?

Please try the following solution.

SQL

-- DDL and sample data population, start
DECLARE @tbl TABLE (ID INT IDENTITY PRIMARY KEY, ParentId1 VARCHAR(MAX));
INSERT INTO @tbl (ParentId1) VALUES
('11.22.33.44.55'),
('11.77.33.44.55');
-- DDL and sample data population, end

DECLARE @separator CHAR(1) = '.'
	, @Level INT = 2;

SELECT t.*
	, c.value('(/root/r[sql:variable("@Level")]/text())[1]', 'VARCHAR(20)') AS result
FROM @tbl AS t
    CROSS APPLY (SELECT TRY_CAST('<root><r><![CDATA[' + 
        REPLACE(ParentId1, @separator, ']]></r><r><![CDATA[') + 
        ']]></r></root>' AS XML)) AS t1(c);

Output