Optional Input Parameter with 'PLACEHOLDER' syntax

Hi

I've created a universe in IDT connecting to a HANA view.  The HANA view contains Input Parameters, as well as Variables.  In my universe I've created a derived table and I use the 'PLACEHOLDER' syntax in the From part of the SQL to cater for the HANA Input Parameters.  I've catered for the
HANA Variables by creating prompts (IDT parameters) in the universe, as well as creating Prompt filters in the Business layer using these parameter prompts.  In doing this, we could choose if we wanted the prompts to be optional or mandatory.

My question is this:  Is there a way to make the Input Parameter which is part of the 'PLACEHOLDER' syntax optional?

Thanks

Alta