<div class="container-1">
    <button class="my-btn" id="red">
        Color1
    </button>
    <button class="my-btn" id="green">
        Color2
    </button>
    <button class="my-btn" id="blue">
        Color3
    </button>
</div>
<hr>
<div class="container-2">
    <button class="my-btn" id="dog">
        Animal1
    </button>
    <button class="my-btn" id="cat">
        Animal2
    </button>
    <button class="my-btn" id="mouse">
        Animal3
    </button>
</div>

sumUp = function(data){
    first = data.btn1;
    second = data.btn2;
    alert('You chose a ' + first + ' ' + second);
};

$(".my-btn").click(function() {
    var val1 = $(this).attr('id');

    $(".container-2 .my-btn").click(function() {
        var val2 = $(this).attr('id');
            });

    var data = {
        btn1: val1,
        btn2: val2
    };

    sumUp(data);
});