create unique select box options syudent conduct form

by davehol

HTML

<div
  role="listbox"
  class="tt-menu"
  id="tfa_1337_listbox"
  aria-expanded="false"
 
>
  <div role="presentation" class="tt-dataset tt-dataset-20">
    <div
      role="option"
      id="tt-4e8bb209-efb4-b8ea-fb9c-7cb5e6a559e5"
      class="tt-suggestion tt-selectable"
    >
      UGRD Semester 1 2020
    </div>
    <div
      role="option"
      id="tt-64eeccf3-5fe9-b7bb-f154-a394ff16a2a3"
      class="tt-suggestion tt-selectable"
    >
      UGRD Semester 1 2020
    </div>
    <div
      role="option"
      id="tt-45107c96-b6a9-de19-ba5f-18936f06cac7"
      class="tt-suggestion tt-selectable"
    >
      UGRD Semester 1 2020
    </div>
    <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2020
    </div>
        <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2022
    </div>
        <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2021
    </div>
        <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2020
    </div>
            <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2022
    </div>
            <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2022
    </div>
            <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion tt-selectable"
    >
      UGRD flexible term 2022
    </div>
            <div
      role="option"
      id="tt-944fd082-a00b-8eb6-98ad-fb5903e5e676"
      class="tt-suggestion...

CSS

#tfa_1337_listbox > div {
  display: flex;
  flex-direction: column;
  flex-direction: column-reverse;
}

JavaScript

var select = document.getElementById("tfa_1337_listbox").children[0].children
var opt = []
var flag = 1
for (let item of select) {
  if (!opt.includes(item.textContent.trim())) {
    opt.push(item.textContent.trim())
  }
}

for (var i = 0; i < opt.length; i++)  {
flag = 0
  for (let item of select) {
    if (item.textContent.trim() == opt[i]) {
      if (flag >= 1) {
      //  console.log("removed")
       item.style.display = 'none';
      }
      flag++
    }
  }
}