How to set a node as context?

I have a little web app where I have two node types:

  • Customers (/customer1, /customer2)
  • Notes about customers

The notes about the customers have an entity reference to the customer. I like to create many notes for a customer without selecting the customer over and over again.

In views I can use a contextual filter.

But how to set a customer as the current permanent context? So that the urls automatically point to the current customer selected and in the node form the customer is selected automatically?

Is there a way to select a customer as my current context? So that every url I click prepends or appends the current customer.

Just like a special area for my selected customer.

Thank you.