Вам нужно найти все кнопки и прокрутить их, чтобы получить их значения.Посмотрите на пример кода ниже, и вы можете получить представление.
$('#bmi_button').click(function(){
var allBtns = $('#bmi_group').find('button');
allBtns.each(function(index, btn){
console.log('Bmi: ', $(btn).val());
})
})
$('#blood_group_button').click(function(){
var allBtns = $('#blood_group').find('button');
allBtns.each(function(index, btn){
console.log('Blood Group: ', $(btn).val());
})
})
var bmi_selected = 0,
blood_group = '';
$('#bmi_group').click(function(e){
bmi_selected = e.target.value;
console.log(e.target.value);
})
$('#blood_group').click(function(e){
bmi_selected = e.target.value;
console.log(e.target.value);
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="btn-group" id="blood_group">
<button type="button" value="ABO" name="blood" class="btn btn-secondary btn-sm active" >All</button>
<button type="button" value="A" name="blood" class="btn btn-secondary btn-sm" >A</button>
<button type="button" value="B" name="blood" class="btn btn-secondary btn-sm">B</button>
<button type="button" value="O" name="blood" class="btn btn-secondary btn-sm" >O</button>
<button type="button" value="AB" name="blood" class="btn btn-secondary btn-sm">AB</button>
<button type="button" value="U" name="blood" class="btn btn-secondary btn-sm" >None</button>
</div>
<br style="clear:both">
<div class="btn-group" id="bmi_group">
<button type="button" value="0" name="bmi" class="btn btn-secondary btn-sm active" >All</button>
<button type="button" value="1" name="bmi" class="btn btn-secondary btn-sm">18.5</button>
<button type="button" value="2" name="bmi" class="btn btn-secondary btn-sm" >18.5-25</button>
<button type="button" value="3" name="bmi" class="btn btn-secondary btn-sm">25-30</button>
<button type="button" value="4" name="bmi" class="btn btn-secondary btn-sm">30-35</button>
<button type="button" value="5" name="bmi" class="btn btn-secondary btn-sm">35-50</button>
<button type="button" value="6" name="bmi" class="btn btn-secondary btn-sm">50+</button>
<button type="button" value="NR" name="bmi" class="btn btn-secondary btn-sm">None</button>
</div>
<button id="bmi_button">get bmi</button>
<button id="blood_group_button"> get bloog groups</button>