Is there a way to use variables set in the Input Values under General in SQL Models?

For instance, if I have input values set up in the collection as "year" and "month", should a SQL Model with

Select {CommonValue_year} as year, {CommonValue_month} as month

return a one record result with the entered values? If not, what are those called? Or do I need a script in the pre-load script to set the common values to the input values?

Thanks.

Where do you declare the common values?

When I go into my report sources 'common restrictions and values', there's no add or remove buttons.