<button id="each">each</button>
<br>
<div id="box">
    <button class="btn">Button-1</button>
    <button class="btn">Button-2</button>
    <button class="btn">Button-3</button>
</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>

#each {
    padding: 10px;
    margin-right: 8px;
    margin-bottom: 18px;
    background-color: tomato;
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

#box {
    border: 1px solid black;
    width: 180px;
    padding: 20px;
}

.btn {
    border: none;
    padding: 10px;
    width: 100%;
    margin-bottom: 10px;
    background-color: darkgrey;
    color: #fff;
}

$(document).ready(function () {
    $("#each").click(function () {
        $("#box button").each(function () {
            var text = $(this).text();
            alert(text);
        });
    });
});