MSSQL server - how to read XML data - XPATH, sql:variable and local-name()

Example xml used for below queries

declare @xml xml
set @xml = '<Document>
 <Main>
  <Field_01>Field_01Value</Field_01>
  <Field_05>Field_05Value</Field_05>
  <TableFields>
   <Table_02>
    <Row>
     <Column_01>Table_02Row_01Col_01Value</Column_01>
     <Column_02>Table_02Row_01Col_01Value</Column_02>
    </Row>
    <Row>
     <Column_01>Table_02Row_02Col_01Value</Column_01>
     <Column_02>Table_02Row_02Col_02Value</Column_02>
    </Row>
   </Table_02>
  </TableFields>
 </Main>
</Document>'

Get the value of Field_01 tag

SELECT @xml.value('(//Field_01/text())[1]', 'nvarchar(max)')

Get the value of field in case you have the field name defined dynamically

declare @field varchar(10)
set @field = 'Field_05'
SELECT @xml.value('(//*[local-name()=sql:variable("@field")]/text())[1]', 'nvarchar(max)')

Similar in case you need value of value of second row of column_01 in table defined dynamically

set @field = 'Table_02'
SELECT @xml.value('(//*[local-name()=sql:variable("@field")]/*/Column_01/text())[2]', 'nvarchar(max)')