The Connections Page is available from the connections menu in the sidebar.
This page shows you all of the starting points for your physical relationships.
A starting point is an asset that is the source of a relationship. This is normally where a product first enters your site (ie. your gas or power provider, for example) or places where a new type of product is created or separated from others (such as filters, screens or ovens).
Click on any of the options to be taken to the diagram for the asset.