There is Azure Resource Graph Explorer which is a very useful tool for auditing cloud resources over multiple subscriptions under the same tenant
Nowadays, Azure Portal does not have any view which provides possibility to understand which resource exactly connected to a Virtual Network because most of resources are attached to Vnet over its Network Interface. So, when we look to Connected Devices tab we see only NICs names and not names of resources.
It possible to make more complex views with KUSTO query language and join information about several resources. In our case, to get the list of VMs with associated Vnets, there are VMs, NICs and VNets:
Resources | where type == "microsoft.compute/virtualmachines" | project name, vmnics = (properties.networkProfile.networkInterfaces) | mv-expand vmnics | project name, vmnics_id = tostring(vmnics.id) | join (Resources | where type == "microsoft.network/networkinterfaces" | project nicname=(name), vmnics_id = tostring(id), properties) on vmnics_id | mv-expand ipconfigs = (properties.ipConfigurations) | extend subnet_resource_id = split(tostring(ipconfigs.properties.subnet.id), '/') | order by name asc, nicname asc | project vmname=(name), nicname, vnetname=subnet_resource_id, subnetname=subnet_resource_id
How to launch the query in Azure Resource Graph Explorer: https://docs.microsoft.com/en-us/azure/governance/resource-graph/first-query-portal