JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <div>
        <input type="radio" name="level0" value="A" id="A"/>
        <label for="A">First Set</label>
        <div class="sub1">
            <div>
                <input type="radio" name="level1" value="A0" id="A0"/>
                <label for="A0">First - Option 1</label>
            </div>
            <div>
                <input type="radio" name="level1" value="A1" id="A1"/>
                <label for="A1">First - Option 2</label>
            </div>
              <div>
                <input type="radio" name="level1" value="A1" id="A1"/>
                <label for="A1">First - Option 3</label>
            </div>
        </div>
    </div>
    <div>
        <input type="radio" name="level0" value="B" id="B"/>
        <label for="B">Second Set</label>
        <div class="sub1">
            <div>
                <input type="radio" name="level1" value="B0" id="B0"/>
                <label for="B0">Second - Option 1</label>
            </div>
            <div>
                <input type="radio" name="level1" value="B1" id="B1"/>
                <label for="B1">Second - Option 2</label>
            </div>
        </div>
    </div>
    <div>
        <input type="radio" name="level0" value="C" id="C"/>
        <label for="C">Third Set</label>
        <div class="sub1">
            <div>
                <input type="radio" name="level1" value="C0" id="C0"/>
                <label for="C0">Third - Option 1</label>
            </div>
            <div>
                <input type="radio" name="level1" value="C1" id="C1"/>
                <label for="C1">Third - Option 2</label>
            </div>
        </div>
    </div>
    <div>
        <input type="radio" name="level0" value="D" id="D"/>
        <label for="D">Fourth Set</label>
        <div class="sub1">
            <div>
                <input type="radio" name="level1" value="D0" id="D0"/>
                <label for="D0">Fourth - Option 1</label>
            </div>
            <div>
           ...

CSS

.sub1, .sub2 { display: none; }

:checked ~ .sub1, :checked ~ .sub2 {
    display: block;
    margin-left: 40px;
}http://jsfiddle.net/user/login/