If you have multiple grow/finisher sites that you would like to have on the same production report shown side by side, you have to do the following setup:

Choose 'General - Production reports'

Create a production report, here illustrated by Code SBS and Name Side by Side. 

Double click on the field Location (Blue box) and a window will open in which you can manually enter the locations that are to show in the report in the white box or use the search function to look through all your current locations.

To run the production report side by side go to Report menu and open the Side by Side report. 

You can here change the from and to dates before you click Calculate.