What is the correct syntax to reference one derived table in the definition of another?

In LookML, when referencing one derived table in the definition of another, the correct syntax is using the specified format along with the SQL_TABLE_NAME attribute of the derived table or view. This is because SQL_TABLE_NAME is specifically used to retrieve the underlying SQL table name associated with a LookML view or derived table.

When you use this syntax, you are essentially instructing Looker to utilize the SQL representation of the derived table for your new definition. This direct reference allows you to maintain clarity and ensure that the SQL generated will accurately use the specified derived table structure, allowing for complex queries and dependencies between derived tables.

The other options do not provide the necessary context or structure to properly reference one derived table within another. For instance, simply using the derived table name without SQL_TABLE_NAME would not provide the complete necessary context needed for the LookML parser to handle that reference correctly.