SQL Server Reporting Services
I am assuming your parameters are named:
Book A
Book B
Book C
Book C will display its valid valid values, after A and B have been selected. On initial display (unless you have defaults) it will appear as though there are none, but after selection of B, C will refresh. C really only has 1 dependency (B), not 2.
Thanks for the reply..But im just curious why my default values become null to the fact that i already have a default value..
I may have misunderstood your question, but it sounds like you are asking why "Book C" is disabled and does not show any values until both "Book A" and "Book B" have been populated.
From your description, C depends on B which depends on A. In this case, RS cannot generate the lists of valid values or default values for C without having values for B because those expressions/queries reference B. After entering a value for B, you should see the default values for C provided they are also in C's valid values list.