1) First of all you have to create new filegroup. To do that add following file to your database project:
DataFileGroup.sql
/* Do not change the database path or name variables. Any sqlcmd variables will be properly substituted during build and deployment. */ ALTER DATABASE [$(DatabaseName)] ADD FILEGROUP [DATA]
2) Navigate to Database project properties in Visual Studio. -> Click "Database settings..."
3) Navigate to "Operational" tab -> Set default filegroup using combo-box with created filegroup on step 1.
