AppiumTests.cs

[TestMethod]
public void LocatingElementInsideAnotherElementTest()
{
    var mainElement = _driver.FindElementById("decor_content_parent");

    var button = mainElement.FindElementById("button");
    button.Click();

    var checkBox = mainElement.FindElementByClassName("android.widget.CheckBox");
    checkBox.Click();

    var thirdButton = mainElement.FindElementByXPath("//*[@resource-id='com.example.android.apis:id/button']");
    thirdButton.Click();
}