Home Assistant in two location, privacy issue

Ha isn’t really designed for delegated administration. You are either an admin, or a user.

There are hacky work around like changing the default dashboard, and creating yaml dashboards(that can’t be edited in the UI) as well as hiding the top bar in the theme. And restricting dashboards to certain users with only the entities you want them to see.

I would maintain two HA instances, one for home, one for office.

Master HA instance with multiple slaves - #60 by Burningstone

If you yourself want to only access one HA instance(so your app works for both), you can connect HA instances as master and slave to forward entities from your office instance to your home HA instance. And then create a dashboard in your home instance only you can access.

But it won’t be fun to maintain.