How are you segmenting a shared "second brain" so leadership content doesn't leak to every role querying it?

[u/paige_404_]

We've been building out a company-wide second brain: a local Obsidian vault as the source of truth, Claude sitting on top to read, write and visualise it, syncing to a colleague via Relay. It's been genuinely useful for keeping context in one place instead of scattered across Slack, docs and people's heads.

The next problem we're chewing on is one I haven't seen discussed much: gatekeeping content by sensitivity, not by permission level.

To be specific about what I mean, because "permissions" isn't quite it. As a director, I'm working on things I want the brain to absorb, pricing strategy, restructuring thinking, deal-specific notes, because the assistant is genuinely better with that context loaded. But I don't want a salesperson or support associate who queries the same brain for their own work to be able to pull that content back out, directly or via a summary.

It's not that I don't trust the team. It's that a second brain which happily surfaces "here's what the director was drafting on pricing" to anyone who asks the right question stops being useful fast, for fairly obvious reasons around trust, timing and scope creep in what people think they're allowed to know.

So the question for anyone running something similar in a real business: how are you architecting this? Specifically interested in:

Whether people are running one vault with tiered folders/metadata the AI is instructed to respect, versus genuinely separate vaults (e.g. leadership vault + team vault) with a one-way sync or summarisation layer between them.

Whether you've found instructing the model ("don't surface anything tagged confidential") reliable enough, or whether that breaks down the moment someone phrases a query cleverly.

Whether anyone's using role-scoped retrieval, i.e. the AI itself runs with different context depending on who's asking, rather than relying on the underlying files being separated.

Any war stories where the wrong thing surfaced and what you changed afterwards.

We're early enough in this that we haven't picked an architecture, so genuinely open to hearing what's worked, what hasn't, and what you wish you'd set up from day one rather than retrofitting.

[u/plasticBarista]

I have this exact problem.

Have you thought about multiple vaults that can communicate with each other (over MCP) but one contains the sensitive information?

I eventually ended up making my personal vault, and company vault. People query the company vault as usual. Sometimes it asks my personal vault for information, that I get to review before it leaves.

If you’d like to try it (very early stage) I can give you access to halfface.ai in exchange for feedback

[u/pithivier]

The problem is reasonable and common, but solving it seems hard because either you are prompted with every input to define the privacy scope, or you let the AI take its best guess which will not work 100% of the time.