I've created one subreport by this article in Report Designer(2.0)

but .. It can't work properly when setting subquery by Teradta(7.2).
It showed the error as below, I guess Teradata couldn't recognize the "parameter " created in main report.
I've been searching soultions on internet ,but still couldn't solve it.
Hope someone can do me a favor .. appreciated .. Thank you ~

couldn't fetch the query metadata.
[Teradata JDBC Driver][TeraJDBC][Error 1074][SQLState HY000]
Invalid Escape Clause "sel * from mciftmp.as_branch where Unit=${UNIT}"