The Connections and Gateways can be viewed in the Power BI portal under the Power BI Settings drop down menu by selecting Manage Connections and Gateways.
On premises data gateways and Connections can be viewed but would be subject to access to the objects themselves.
Access can be added for Gateways through the option to Manage users.
The status for gateways and connections can also be checked, these do have to be in an Online state for Connections migrations.
The Semantic Models which store the reporting data and have the Connection information can be viewed in the portal for specific workspaces by accessing the workspace and then selecting to view the Settings for the Semantic Model(s).
The Semantic Model Settings will show the connection that is being used for the data refresh from the source system. This can be referenced on under Manage Connections and Gateways in Power BI.
