How to call a step from another step in Cucumber-JVM

This functionality is not supported in Cucumber-JVM. (Note that the Cucumber Backgrounder document you link in your question describes using Steps within Steps as "an anti-pattern")

Essentially, we believe that Cucumber is a collaboration tool and that Gherkin is not a programming language.

You can see a longer discussion of how we arrived at this decision here

To call steps within step definitions, inherit cuke4duke.Steps in java

import cuke4duke.StepMother;
import cuke4duke.Steps;
import cuke4duke.annotation.I18n.EN.When;

public class CallingSteps extends Steps {
    public CallingSteps(StepMother stepMother) {
        super(stepMother);
    }

    @When("^I call another step$")
    public void iCallAnotherStep() {
        Given("it is magic"); // This will call a step defined somewhere else.
    }
}

Example: https://github.com/cucumber-attic/cuke4duke/blob/master/examples/java/src/test/java/simple/CallingSteps.java

Note: cuke4duke support scala as well