Multiple divisions can be handled by setting up separate analyses for each division. You can then use the consolidation feature to create a consolidated budget for all thirty restaurants.
Creating 30 analyses from scratch could be an onerous task. With this in mind here are two short cuts that should save you a bunch of time.
1. Don't create each analysis from scratch. I would suggest that you set up a template analysis that has all the correct setup options. From there use the File>Save As functionality to create each analysis. Using the Save As functionality ensures that the setup options will be held constant for each analysis, thus ensuring that the consolidation works properly, and it will be a big time saver.
2. If you are importing from excel and have a common chart of accounts across all divisions you can link your Excel chart of accounts to your PlanGuru categories once in your template analysis. Then as you create new analyses using the Save As functionality the association you established in your template will be carried over to the new analysis analysis. You will still need to import data from the appropriate Excel chart of accounts, but so long as the accounts are exactly the same you won't have to go through the trouble of re-linking the matching accounts. Clearly accounts that are not found in your template will need to be linked.