Selection of a specific object with the same classes

[rielyn]

It is necessary to obtain a specific element with class (b) when the courseor is established, not all elements immediately.

And I get everything.

 
 $(".a").hover(function() {
        $(".b").css({"position":"relative","top":"0px"});
 }, function() {
  $(".b").css({"position":"relative","top":"-40px"});
 });

<div class="a">
  <div class="b"></div>
</div>
<div class="a">
  <div class="b"></div>
</div>
<div class="a">
  <div class="b"></div>
</div>
<div class="a">
  <div class="b"></div>
</div>

[briley]

Use your function. http://jquery-docs.ru/Traversing/children/

$(".a").hover(function() {
  $(this).children(".b").css({
    "position": "relative",
    "top": "0px"
  });
}, function() {
  $(this).children(".b").css({
    "position": "relative",
    "top": "-40px"
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="a">

<div class="b"></div>

</div>

<div class="a">

<div class="b"></div>

</div>

<div class="a">

<div class="b"></div>

</div>

<div class="a">

<div class="b"></div>

</div>