Nested paths on data type expressions?

I created a data type in which I will have a parameter to indicate an alarm condition. I want to use it with an indirect reference, so that that the Index will be used in the tag path on each instance as follows:


This produces an error in the instance “Nested paths not allowed”
Error configuring tag for execution. Error:
Scan Error: Nested paths not allowed. (Line 1 , Char 25)

Is there another way to do this?

Replace your curly braces with regular parenthesis.

Thanks for your replies. I fixed the problem; the function tag() requires parens and the parameter Index requires curly braces.