<button class="btn" data-modal="modal1">Кнопка #1</button>
  <button class="btn" data-modal="modal2">Кнопка #2</button>
  <button class="btn" data-modal="modal3">Кнопка #3</button>
  
  <div class="button_block" modal="modal1">Блок 1</div>
  <div class="button_block" modal="modal2">Блок 2</div>
  <div class="button_block" modal="modal3">Блок 3</div>

button {
  background: tomato;
  outline: 0;
  border: 0;
  padding: 15px 25px;
  display: inline-block;
  margin: 10px;
  cursor: pointer;
}

.button_block {
  display: none;
  padding: 50px 0;
  text-align: center;
}
.button_block.active {
  background: gray;
}
.active {
  display: block;
}

$(document).ready(function() {
  $('.btn').on('click', function(){
    var modal_index = $(this).data('modal');
    $(`.button_block[modal="${modal_index}"]`).toggleClass('active')
    .siblings()
    .removeClass('active');
  });
    
});