html

<ul class="list-group" style="width: 15%">
        <li class="list-group-item list-group-item-action  my-1">
            <details>
                <summary>
                    iFIX
                </summary>
                <ul>
                    <li class="items">iFIX5.9.ISO</li>
                    <li class="items">iFIX6.0.ISO</li>
                </ul>
            </details>

        </li>

        <li class="list-group-item list-group-item-action  my-1">
            <details>
                <summary>
                    Historian
                </summary>
                <ul>
                    <li class="items">Historian7.0.ISO</li>
                </ul>
            </details>
        </li>

    </ul>