bootstrap validtion in multiple input feilds inside a form but if one feild is filled then skip validation code example

Example: input with bootstrap

<form>
  <div class="form-group">
    <label for="exampleInputEmail1">Email address</label>
    <input type="email" class="form-control">
    <small id="emailHelp" class="form-text text-muted">Hello, World</small>
  </div>
 </form>