[Nexus]

<div class="phone_number">
	+7495333<span data-value="2211">xxxx</span>
	<span class="phone_number_active">Показать</span>
</div>
<div class="phone_number">
	+7495333<span data-value="2211">xxxx</span>
	<span class="phone_number_active">Показать</span>
</div>
<script>
[].forEach.call(document.querySelectorAll('.phone_number'),function(node){
	node.querySelector('.phone_number_active').addEventListener('click',function(){
		const nums=node.querySelector('[data-value]');
		nums.textContent=nums.dataset.value;
		
		this.style.display='none';
	});
});
</script>