<div class="navigation">
  <ul>
    <script>
      let icons = ["home", "person", "chatbubble", "camera", "settings"]
      for (let i of icons) {
        document.write(`<li><a href="#"><span class="icon"><ion-icon name="${i}-outline"></ion-icon></span></a></li>`)
      }
    </script>
    <div class="indicator"><span></span></div>
  </ul>
</div>

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --clr: #fff;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: var(--clr);
}

.navigation {
  width: 420px;
  height: 70px;
  background: #209cff;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  border-radius: 10px;
}

.navigation ul {
  position: relative;
  display: flex;
  width: 350px;
}

.navigation ul li {
  position: relative;
  list-style: none;
  width: 70px;
  height: 70px;
  z-index: 1;
}

.navigation ul li a {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
}

.navigation ul li a .icon {
  position: relative;
  display: block;
  font-size: 1.5em;
  color: #fff;
  line-height: 75px;
  opacity: 0.75;
  transition: 0.5s;
}

.navigation ul li.active a .icon {
  opacity: 1;
  color: #209cff;
  transform: translateY(-8px);
}

.indicator {
  position: absolute;
  top: -10px;
  width: 70px;
  height: 70px;
  background: var(--clr);
  border-bottom-left-radius: 35px;
  border-bottom-right-radius: 35px;
  border: 6px solid var(--clr);
  cursor: pointer;
  transition: 0.5s;
}

.indicator::before {
  content: "";
  position: absolute;
  top: 4px;
  left: -25.75px;
  width: 20px;
  height: 20px;
  background: transparent;
  border-top-right-radius: 20px;
  box-shadow: 4px -6px 0 2px var(--clr);
}

.indicator::after {
  content: "";
  position: absolute;
  top: 4px;
  right: -25.75px;
  width: 20px;
  height: 20px;
  background: transparent;
  border-top-left-radius: 20px;
  box-shadow: -4px -6px 0 2px var(--clr);
}

.indicator span {
  position: absolute;
  left: -1px;
  width: 60px;
  height: 60px;
  border: 4px solid #209cff;
  border-radius: 50%;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
  transform: scale(0.85);
}

.navigation ul li:nth-child(3).active ~ .indicator {
  transform: translateX(calc(70px * 1));
}

.navigation ul li:nth-child(4).active ~ .indicator {
  transform: translateX(calc(70px * 2));
}

.navigation ul li:nth-child(5).active ~ .indicator {
  transform: translateX(calc(70px * 3));
}

.navigation ul li:nth-child(6).active ~ .indicator {
  transform: translateX(calc(70px * 4));
}

let list = document.querySelectorAll(".navigation li");
list[0].classList.add("active");

function activeLink() {
  list.forEach((item) => item.classList.remove("active"));
  this.classList.add("active");
}

list.forEach((item) => item.addEventListener("click", activeLink));