I am wondering, is it possible to configure DataProvider/Resource/List to support REST urls like api/users/1/roles?
For RESTful API it is very common us
TL;DR: By default, React Admin doesn't support nested resource, you have to write a custom data provider.
This question was answered on a past issue: maremelab/react-admin#261
Detailed Answer
The default data provider in React Admin is ra-data-simple-rest.
As explained on its documentation, this library doesn't support nested resources since it only use the resource name and the resource ID to build a resource URL:
In order to support nested resources, you have to write your own data provider.
Nested resources support is a recurrent feature request but, at the time, the core team don't want to handle this load of work.
I strongly suggest to gather your forces and write an external data provider and publish it like ra-data-odata provider. It would be a great addition and we will honored to help you with that external package.