Hi,
The Schema Mapping functionality only works for the HANA Views (Attribute View, Analytic View, Graphical Calculation View etc.).
If you are creating and files like .hdbprocedure then the schema mapping functionality does not work. To get around this issue, you should create public synonyms for the tables which you want to use in the procedure and use the synonym instead of the table in the procedure.
Please note that you will have to create the synonyms with the same name in each environment.
Thanks
Sandeep