Needing to block out part of a camera's view can be achieved by enabling Privacy Zones. This feature will block out portions of the camera's live feed and historical footage. It will first need to be enabled for the org before it can be enabled on the cameras.
Note: You will need to have Site Admin permissions to configure Privacy Zones for a camera
Configuring Privacy Zones
Navigate to the camera you want to configure.
Select the Info button and then choose Settings.
Select the Privacy tab.
Toggle Enable Privacy Zones.
Using the grid, click and drag over the area you want to hide. You will see a black box drawn over the area.
Select Apply. The camera may take a minute or two to update its configuration, after which you will see the privacy zones on the camera's live feed and associated historical video going forward (i.e. the privacy zone is not retroactive).