Which hotels a person sees
Tick the hotels somebody works at. They see those and no others. An administrator sees every hotel.
In a group with several hotels, a person sees exactly the hotels ticked for them, and no others. The ticks are on step 2 of the Add a person wizard, and on Job & access for somebody already on the team.

- At least one hotel must be ticked. A login with none would open to an empty screen and look broken, so the wizard refuses it.
- The first hotel ticked is the code they type at sign-in.
- Administrators work in every hotel of the group. There is nothing to tick for them.
- The restriction is enforced in the database, not on the screen. A person without the tick cannot reach that hotel's bookings, bills or guests through any route in the product.
To stop somebody working here, Disable the login rather than unticking every hotel. That keeps their history against the bookings they took.
A person who says a hotel has "disappeared" has usually been scoped correctly for the first time.