Jquery select this + class

Use $(this).find(), or pass this in context, using jQuery context with selector.

Using $(this).find()

$(".class").click(function(){
     $(this).find(".subclass").css("visibility","visible");
});

Using this in context, $( selector, context ), it will internally call find function, so better to use find on first place.

$(".class").click(function(){
     $(".subclass", this).css("visibility","visible");
});