Multiple Knowledge Sheet Documents handled by one chatbot

I want to build a chatbot on Voiceflow or other providers for our company with tons of different knowledge sheet components.
The problem is that this knowledge consists of multiple data that partly has little to nothing to do with each other. So say one knowledge is about FAQs one is about technical trial and errors etc. so Sales, Aftersales, Lead Generation - all within one bot basically.
So the main question is how to organize the knowledge within one bot in the most structured way (maybe also when it coems to the custom instructions of the bot) - Preferably I would need a bot system where there is a defined set of knowledge for every path and not ONLY for the entire Bot. Hope you got what I am referring to.

Once a chat with the Bot is started, can user ask about different topics in same chat? Lets say User started the chat with Assistant to know details about ‘FAQs’ and then in the middle of conversation switches back to ‘technical trial and errors’. Will that be a case in your scenario?

No it can be seperated so the flow would be in a way that you have to decide on your interest why you are contacting so the only way of asking a question like that (so if I am on the Aftersales path and asking about a Sales related interest it would catch that intent as NOT AFTERSALES INTENT and go back to the start)

You can create multiple Assistants with different attached Vector Stores but a better approach will be have a single assistant without any vector store attached to it and then create a thread and attach Vector Store to it depending upon the interest of the User.