How to keep focus on a custom dropdown after making selection?

for (const dropdown of document.querySelectorAll(".custom__select-wrapper:not(.clearFilter)")) {
  dropdown.addEventListener("click", function () {
    this.querySelector(".custom__select").classList.toggle("open");
  });
}

for (const option of document.querySelectorAll(".custom__option")) {
  option.addEventListener("click", function () {
    if (!this.classList.contains("selected")) {
      this.parentNode
        .querySelector(".custom__option.selected")
        .classList.remove("selected");
      this.classList.add("selected");
      this.closest(".custom__select").querySelector(
        ".custom__select-trigger h6"
      ).textContent = this.textContent;
      if (this.getAttribute("data-type")) {
        current_story = this.dataset["type"];
      }
    }
  });
}

window.addEventListener("click", function (e) {
  for (const select of document.querySelectorAll(".custom__select")) {
    if (!select.contains(e.target)) {
      select.classList.remove("open");
    }
  }
});

@charset "UTF-8";
nav ul {
  list-style-type: none;
  display: flex;
  flex-direction: row;
  width: 100%;
  justify-content: space-evenly;
}

.content {
  display: flex;
  flex-direction: column;
  align-items: center;
}

button.clear {
  border: 0;
  background: #fff;
}

#selectedFilter {
  color: #005fec;
}

ul {
  padding-left: 0;
  margin: 0;
}

.filter {
  padding-right: 15px;
  padding-left: 15px;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
}
@media (min-width: 768px) {
  .filter__settings {
    display: flex;
    flex-direction: row;
    border-top: 1px solid #E0E5EC;
    border-bottom: 1px solid #E0E5EC;
  }
}

.custom__select {
  position: relative;
  display: flex;
  flex-direction: column;
}
@media (min-width: 768px) {
  .custom::before, .custom__options {
    transition: all 0.2s ease-in;
  }
}
.custom__select-wrapper {
  position: relative;
  user-select: none;
  padding: 0;
  border-bottom: 1px solid #E0E5EC;
}
.custom__select-wrapper:last-child {
  border: 0;
}
.custom__select-wrapper.clearFilter {
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.custom__select-wrapper .selected-clearFilter {
  position: relative;
  user-select: none;
  padding: 1rem 0 !important;
}
@media (min-width: 768px) {
  .custom__select-wrapper {
    padding: 0 2em;
    border: 0;
    display: flex;
    justify-content: center;
    align-items: center;
  }
  .custom__select-wrapper:first-child, .custom__select-wrapper:last-child {
    padding: 0;
  }
}
.custom__select-wrapper h6 {
  padding: 20px 3px;
  color: #62668C;
  font-weight: 300;
}
.custom__select-trigger {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}
@media (min-width: 768px) {
  .custom__select-trigger {
    justify-content: space-evenly;
    margin-right: auto;
  }
}
.custom__select-wrapper h6, .custom__select-trigger h6 {
  font-size: 0.75rem;
  line-height: 0.75rem;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 20px 0;
}
.custom__select-trigger h6 {
  color: #005fec;
  font-weight: 900;
}
.custom__select-wrapper #selectedFilter {
  font-size: 12px;
  line-height: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: #005fec;
  font-weight: 800;
  padding: 0;
}
.custom__options {
  display: none;
  top: 100%;
  left: 0;
  right: 0;
  border-top: 0;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  z-index: 2;
  color: #E0E5EC;
}
@media (min-width: 768px) {
  .custom__options {
    display: unset;
    position: absolute;
    background-color: #005fec;
    max-height: 320px;
    overflow-y: scroll;
  }
  .custom__options#storyFilter {
    overflow: hidden;
  }
}
.custom__options.active {
  display: block;
  visibility: visible;
  opacity: 1;
  z-index: 10;
}
.custom__select-trigger, .custom__option {
  letter-spacing: 1px;
  font-weight: 800;
  color: #005fec;
  border: 0;
  background: transparent;
}
@media (min-width: 768px) {
  .custom__select.open::before {
    content: "";
    position: absolute;
    bottom: 0;
    left: 11px;
    border-left: 11px solid transparent;
    border-right: 11px solid transparent;
    border-bottom: 11px solid #005fec;
  }
}
.custom__select .custom__options {
  min-width: 15rem;
}
.custom__select.open .custom__options {
  display: block;
  opacity: 1;
  visibility: visible;
  pointer-events: all;
  color: #fff;
  min-width: 15rem;
}
@media (min-width: 768px) {
  .custom__select.open .custom__options {
    display: unset;
    box-shadow: 0px 12px 30px rgba(0, 0, 0, 0.12);
  }
}
.custom__option {
  position: relative;
  display: block;
  padding: 0 22px 0 12px;
  font-weight: 400;
  color: #62668C;
  cursor: pointer;
  font-size: 1rem;
  line-height: 1rem;
  margin: 1.5rem 0;
}
@media (min-width: 768px) {
  .custom__option {
    font-size: 1.25rem;
    line-height: 1.25rem;
    color: white;
    font-weight: 300;
    padding: 0 22px 0 20px;
  }
  .custom__option a {
    color: white !important;
    text-decoration: none;
  }
}
.custom__option:hover {
  cursor: pointer;
}
.custom__option.selected {
  color: #005fec;
}
@media (min-width: 768px) {
  .custom__option.selected {
    color: #ffffff;
  }
}
.custom__option.selected::before {
  content: "•";
  margin-left: -12px;
  padding-right: 8px;
}

.empty-state {
  width: 100%;
  display: flex;
  background: #005fec;
  padding: 1rem;
  border-radius: 4px;
  align-items: center;
  margin: 2rem 0.5rem;
}
.empty-state h4 {
  color: white;
  font-size: 1rem;
  line-height: 1.5rem;
  font-weight: 300;
  margin-left: 0.5rem;
}
.empty-state h4 span {
  color: white;
  text-decoration: underline;
  cursor: pointer;
}

.arrow {
  position: relative;
  height: 5px;
  width: 3px;
  margin-left: 0.5rem;
  margin-bottom: 0.1rem;
}
.arrow::before, .arrow::after {
  content: "";
  position: absolute;
  bottom: 0px;
  width: 0.1rem;
  height: 100%;
  transition: all 0.45s;
}
.arrow::before {
  left: 0px;
  transform: rotate(45deg);
  background-color: #005fec;
}
@media (min-width: 768px) {
  .arrow::before {
    left: 7px;
  }
}
.arrow::after {
  left: -2.5px;
  transform: rotate(-45deg);
  background-color: #005fec;
}
@media (min-width: 768px) {
  .arrow::after {
    left: 4.5px;
  }
}

.open .arrow::before {
  left: 0px;
  transform: rotate(-45deg);
}
@media (min-width: 768px) {
  .open .arrow::before {
    left: 7px;
  }
}
.open .arrow::after {
  left: -2.5px;
  transform: rotate(45deg);
}
@media (min-width: 768px) {
  .open .arrow::after {
    left: 4.5px;
  }
}

<div class="container">
  <nav>
    <ul>
      <li><a href="#">Home</a></li>
      <li><a href="#">About</a></li>
      <li><a href="#">Products</a></li>
      <li><a href="#">Sales</a></li>
      <li><a href="#">Contact</a></li>
    </ul>
  </nav>
  <section class="content">
    <h2 class="title">Hello World</h2>
    <h6 class="subtitle">Lorem ipsum dolor sit amet.</h6>
  </section>
  <section class="filter">
    <div class="filter__settings">
      <div class="custom__select-wrapper">
        <h6>filter by</h6>
      </div>
      <div class="custom__select-wrapper">
        <div class="custom__select story-sel selector" role="menubar">
          <button class="custom__select-trigger" aria-haspopup="true" aria-expanded="false" id="storySelector">
            <h6>Story Type</h6>
            <div class="arrow"></div>
          </button>
          <ul class="custom__options dropdown story-selector" id="storyFilter" aria-label="submenu" role="menu" aria-labelledby="custom-dropdown">
            <li role="menuitem" class="custom__option selected" data-type="all" id="storyItem_all"><a href="javascript:void(0);">All</a>
            </li>
            <li role="menuitem" class="custom__option" data-type="news" id="storyItem_nm"><a href="javascript:void(0);">News and
                media</a></li>
            <li role="menuitem" class="custom__option" data-type="analysis" id="storyItem_analysis"><a href="javascript:void(0);">Analysis</a></li>
            <li role="menuitem" class="custom__option" data-type="press" id="storyItem_pr"><a href="javascript:void(0);">Press
                releases</a></li>
          </ul>
        </div>
      </div>
      <div class="custom__select-wrapper">
        <div class="custom__select year-sel selector">
          <button type="button" class="custom__select-trigger" id="yearSelector">
            <h6>Year</h6>
            <div class=" arrow"></div>
          </button>
          <ul class="custom__options dropdown year-selector" id="yearSelection" aria-label="submenu" role="menu" aria-labelledby="custom-dropdown">
            <li role="menuitem" class="custom__option selected" data-year="all"><a href="javascript:void(0);">All</a></li>
            <li role="menuitem" class="custom__option" data-year="2021"><a href="javascript:void(0);">2021</a></li>
            <li role="menuitem" class="custom__option" data-year="2020"><a href="javascript:void(0);">2020</a></li>
            <li role="menuitem" class="custom__option" data-year="2019"><a href="javascript:void(0);">2019</a></li>
          </ul>
        </div>
      </div>
    </div>
  </section>
</div>