Execute the stored procedure as follows
EXEC [dbo].[spotlight_rep_growth_data_files2]
@start_date = N'jan 1 2015',
@end_date = N'dec 31 2015',
@monitored_object_name = N'host_instance_sqlserver',
@database_size = 10
The monitored_object_name format can be:
<host name>_<instance name>_sqlserver
<host name>_sqlserver