JSFiddle - React, Tailwind, and code Playground

HTML

<form class="form" method="POST">
  <div class="block">
        Entry 1<br><input type="text" name="myInputs"><br>
        <div class="buttons">
          <input class="add_sub_button" type="button" value="add nested">
          <input class="add_button" type="button" value="Add another text input" >
        </div>
  </div><br />
        <input type="submit" value = "answer" multiple="multiple"/>
</form>

CSS

div.block{
  padding:5px;
  border:2px solid #000;
}

JavaScript

var counter = 1;
function addNode(element) {
	counter++;
  var new_entry="Entry "+counter+"<br><input type='text' name='myInputs'><br>";
  element.insertAdjacentHTML("beforebegin",new_entry);
}
function addSub(element) {
	counter++;
	var new_sub_entry="<div class='block'>"
  								+"Entry "+counter+"<br><input type='text' name='myInputs'><br>"
                  +"<div class='buttons'>"
                  +"<input class='add_sub_button' type='button' value='add nested'>"
                  +"<input class='add_button' type='button' value='Add another text input' >"
                  +"</div>"
                  +"</div><br />"
                  +"</div>";
  element.insertAdjacentHTML("beforebegin",new_sub_entry); 
  var blocks=element.parentNode.getElementsByClassName("block");
  blocks[blocks.length-1].getElementsByClassName("add_sub_button")[0].addEventListener("click",function(){
  	addSub(this.parentNode);
  });
  blocks[blocks.length-1].getElementsByClassName("add_button")[0].addEventListener("click",function(){
  	addNode(this.parentNode);
  });
}

var buttons=document.getElementsByClassName("add_button");
for(i=0;i<buttons.length;i++){
	buttons[i].addEventListener("click",function(){
  		addNode(this.parentNode);
  });
}
var nested_buttons=document.getElementsByClassName("add_sub_button");
for(i=0;i<buttons.length;i++){
	nested_buttons[i].addEventListener("click",function(){
  		addSub(this.parentNode);
  });
}