JSFiddle - React, Tailwind, and code Playground

HTML

<form action="#" method="post" id="adminForm" name="adminForm" class="form-auto m-0 cb_form cbValidation" novalidate="novalidate">
     <input type="hidden" name="listid" value="6">
     <input type="hidden" name="limitstart" value="0">
     <input type="hidden" name="search" value>
     <select id="cb_degree" class="cb_select" required>
       <option value="" selected>No preference</option>
       <option value="chem" class="search-btn" data-search="chemistry">chemistry</option>
       <option value="phys" class="search-btn" data-search="physics">physics</option>
       <option value="math" class="search-btn" data-search="mathematics">mathematics</option>

     </select>
     <select id="cb_country" class="cb_select" required>
       <option value="" selected>No preference</option>
       <option value="us" class="search-btn" data-search="USA">USA</option>
       <option value="fr" class="search-btn" data-search="France">France</option>
       <option value="ge" class="search-btn" data-search="Germany">Germany</option>

     </select>
     <select id="cb_state" class="cb_select" required>
       <option value="" selected>No preference</option>
       <option value="ny" class="search-btn" data-search="New York">New York</option>
       <option value="par" class="search-btn" data-search="Paris">Paris</option>
       <option value="frank" class="search-btn" data-search="Frankfurt">Frankfurt</option>

     </select>
     <select id="cb_religion" class="cb_select" required>
       <option value="" selected>No preference</option>
       <option value="chr" class="search-btn" data-search="Christianity">Christianity</option>
       <option value="hin" class="search-btn" data-search="Hinduism">Hinduism</option>
       <option value="bud" class="search-btn" data-search="Buddishm">Buddishm</option>

     </select>
     <input type="submit" id="submit" value="Find Users" class="cbUserlistSubmit" disabled="disabled" />
   </form>
   <div id="test">
   </div>

CSS

* { box-sizing: border-box; }

input {
  display: block;
  width: 100%;
  padding: 14px 16px;
  border-top: 0;
  border-left: 1px solid #ccc;
  border-right: 1px solid #ccc;
  border-bottom: 1px solid #ccc;
  background: #fff;
}

input[type="submit"] {
  width: 100%;
  padding: 14px 16px;
  background: #5cb85c;
  color: #fff;
  border: 0;
  border-radius: 0;
  margin-bottom: 20px;
  transition: background 600ms;
  margin-top: 10px;
  cursor: pointer;
}

input[type="submit"]:disabled {
  background: #555;
  cursor: not-allowed;
}

JavaScript

(function() {
  if ($('input[name=listid]').val() === '6') {
    $('#adminForm').on("change keyup", function(event) {
      var empty = false;
      $('#adminForm > select').each(function() {
        if ($(this).val() == '') {
          empty = true;
        }
      });
      if (empty) {
        $('.cbUserlistSubmit').attr('disabled', 'disabled');
      } else {
        $('.cbUserlistSubmit').removeAttr('disabled');
      }
    })
  };
})();