JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.4.1.slim.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.css">
<div id="progress-bar-fiddle" class="container pt-4">
  <div class="row">
    <div class="col">
      <div style="postion: relative;">
        <div id="progress-bar" class="progress">
          <div id="actual-progress" class="progress-bar actual"></div>
          <div id="projected-progress" class="progress-bar projected"><div>
        </div>
      </div>
    </div>
  </div>
  
  <div class="row mt-2">
    <div id="limits" class="col d-flex flex-row"></div>
  </div>
</div>

CSS

#progress-bar-fiddle {
  --actual-colour: #b445f5;
  --projected-colour: #d391fa;
  --progress-height: 25px;
}

.progress-bar.actual {
  background: var(--actual-colour);
}

.progress-bar.projected {
  background: var(--projected-colour);
  position: relative;
}

.projected.progress-overlap::before {
  width: calc(var(--progress-height) / 2);
  height: var(--progress-height);
  border-radius: 0 500px 500px 0;
  background-color: var(--actual-colour);
  position: absolute;
  content: '';
}

.actual.progress-overlap {
  border-radius: 0;
}

.progress-bar {
  border-radius: 0 500px 500px 0;
}

.progress {
  border-radius: 500px !important;
  height: var(--progress-height) !important;
}

.limit {
  border-right: 1px solid black;
  height: 20px;
  text-align: center;
 }

JavaScript

const data = {
  actual: 1500,
  projected: 2000,
  limits: [500, 1500, 3000]
};

const limitMax = Math.max(...data.limits);

const limitsDiv = document.getElementById("limits");
data.limits.forEach((limit, index, limits) => {
  const limitSize = index ? limit - limits[index - 1] : limit;
  
	const limitDiv = document.createElement("div");
  limitDiv.classList.add("limit");
  limitDiv.style.width = `${(limitSize / limitMax) * 100}%`;
  limitDiv.innerText = limit;
  
  limitsDiv.appendChild(limitDiv);
})

const actualProgress = document.getElementById("actual-progress");
const projectedProgress = document.getElementById("projected-progress");

var actualPercentage;
var projectedPercentage;

if (data.actual === 0) {
	actualPercentage = 0;
  projectedPercentage = Math.min(data.projected, limitMax) / limitMax;
}
else if (data.actual >= limitMax) {
	actualPercentage = 1;
  projectedPercentage = 0;
}
else {
	actualPercentage = data.actual / limitMax;
  projectedPercentage = (Math.min(data.projected, limitMax) - data.actual) / limitMax;
}

actualPercentage *= 100;
projectedPercentage *= 100;
const overlapWidthPx = document.getElementById("progress-bar").clientHeight / 2;

if (data.actual > 0 && data.actual < limitMax) {
	actualProgress.classList.add('progress-overlap');
  projectedProgress.classList.add('progress-overlap');
  
	actualProgress.style.width = `calc(${actualPercentage}% - ${overlapWidthPx}px)`;
	projectedProgress.style.width = `calc(${projectedPercentage}% + ${overlapWidthPx}px)`;
}
else {
	actualProgress.style.width = `${actualPercentage}%`;
  projectedProgress.style.width = `${projectedPercentage}%`;
}

const formatPercentage = number => `${Math.round((number + Number.EPSILON) * 100) / 100} %`

actualProgress.innerText = formatPercentage(actualPercentage);
projectedProgress.innerText = formatPercentage(actualPercentage + projectedPercentage);