Every Unit has a History tab. The history tab displays records of Unit position in the Units hierarchy. If the Unit gets moved (its position in the hierarchy is changed), it's recorded in this tab. The list of History does not contain records of the Unit creation and movements before implementing this bookmark's display and functionality.
It is possible for the users to see this tab in the Unit profile when a person has permission to read it or it is set to visible for all users in Administration/Settings/Unit data.
When the Unit History tab is set to Visible in the Administration, all the users in the system see it among the other Unit tabs, also people without this permission. When the Unit History tab is not set to Visible, only people with this permission are able to see it.