Map Controls
The map has three buttons

The first two are pretty self-explanatory, they zoom the map in and out.
The behaviour of the fit button however is context specific. What it fits depends on the state of the page. When nothing is selected it will fit the map to contain all contents. When a layer card is expanded it will fit the map to contain its layer boundary if it has one. When the item view is open then it will fit the map to contain all the items, this will take filtering into account too. Finally, when an individual item is selected then it will fit the map to contain that item.