Let's have a structure
{
"services": {
"service": [
{
"type": "config:test",
"instance": [

{ "name": "testName", "provider": "testProvider" }

]
},
...

GET request with query parameter fields=service(type;instance/name;instance/provider) results in error "Child instance node missing in instance".

Request with fields=service(type;instance(name;provider)) is working fine.

Both of them should work.