It seems to me that I found the solution:

DECLARE @XML XML

DECLARE @ElementName VARCHAR(20)

SET @ElementName = 'city'

SELECT @XML = '

<employees>

<employee>

<name>Jacob</name>

<city>NY</city>

...

DECLARE @XML XML

DECLARE @ElementName VARCHAR(20)

SET @ElementName = 'city'

SELECT @XML = '

<employees>

<employee>

<name>Jacob</name>

<city>NY</city>

<team>SQL Server</team>

</employee>

<employee>

...