container container-root {
    ...
    container container-lvl1 {
      ...
    }
  }

  augment /tm:container-root/tm:container-lvl1 {
    container container-aug {
      leaf leaf-aug {
        type string;
      }
      ...
    }
  }

{
    "ietf-yang-patch:yang-patch": {
        "patch-id": "test-patch",
        "comment": "comment",
        "edit": [
            {
                "edit-id": "edit1",
                "operation": "replace",
                "target": "/test-model:container-root/test-model:container-lvl1/test-model-aug:container-aug",
                "value": {
                    "container-aug": {
                        "leaf-aug": "data"
                    }
                }
            }
        ]
    }
}

14:27:21.286 WARN [qtp910831865-121] /rests/data/network-topology:network-topology/topology=topology-netconf/node=device/yang-ext:mount
javax.servlet.ServletException: javax.servlet.ServletException: java.lang.IllegalArgumentException: Could not find schema for node (test-ns-aug)container-aug in container container-aug
	at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:90) ~[?:?]
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) ~[bundleFile:9.4.28.v20200408]
	at org.eclipse.jetty.server.Server.handle(Server.java:500) ~[bundleFile:9.4.28.v20200408]
	...
Caused by: javax.servlet.ServletException: java.lang.IllegalArgumentException: Could not find schema for node (test-ns-aug)container-aug in container container-aug
	at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:432) ~[?:?]
	at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:370) ~[?:?]
	at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:389) ~[?:?]
    ...
Caused by: java.lang.IllegalArgumentException: Could not find schema for node (test-ns-aug)container-aug in container container-aug
	at com.google.common.base.Preconditions.checkArgument(Preconditions.java:441) ~[?:?]
	at org.opendaylight.yangtools.yang.data.impl.codec.SchemaTracker.getSchema(SchemaTracker.java:153) ~[?:?]
	at org.opendaylight.yangtools.yang.data.impl.codec.SchemaTracker.startContainerNode(SchemaTracker.java:233) ~[?:?]
    ...

                "target": "/test-model:container-root/test-model:container-lvl1/test-model-aug:container-aug/test-model-aug:leaf-aug",
                "value": {
                    "leaf-aug": "data"
                }

                "target": "/test-model:container-root/test-model:container-lvl1",
                "value": {
                    "container-lvl1": {
                        "container-aug": {
                            "leaf-aug": "data"
                        }
                    }
                }