DDim1000,
<!doctype html>
<html lang="ru">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<div>
<div class="countries_capitals">
<div class="countrie_capital">
<div class="country">
<p>Россия</p>
</div>
<div class="capital">
<p>Москва </p>
</div>
</div>
</div>
<div class="countrie_capital">
<div class="name_capitals">
<div class="country">
<p>США</p>
</div>
<div class="capital">
<p>Вашингтон </p>
</div>
</div>
</div>
<div class="countrie_capital">
<div class="name_capitals">
<div class="country">
<p>Германия</p>
</div>
<div class="capital">
<p>Берлин </p>
</div>
</div>
</div>
</div>
<script>
var Countries = document.querySelectorAll(".countrie_capital");
for(const el of Countries) {
const a = [...el.querySelectorAll(".country, .capital")].map(({textContent}) => textContent.trim());
document.write(`${a}<br>`)
}
</script>
</body>
</html>