1 of 1 people found this helpful
I am not sure what relationship structures you may need, lacking any idea of what you currently have in place, but you can do Record-Level locking of records for both editing and viewing within the Security/permissions settings. Each company's records would need a company identifier within the record which would be used to restrict company's users so each could see or edit only the records with their company ID, but it's all doable.
Caveat: Is this is a good scalability idea? It may be useful with a single manager at this point, but at some point there may be good reason for the different companies to have separate file systems. Is it likely that more companies will be added who want identical functionality, or more likely that they are going to need to be reseparated down the road.