ruzik,
<!DOCTYPE HTML>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(function () {
$('div.myDiv button').filter(function () {
return $(this).text() == "myText"
}).css("background-color", "red");
})
</script>
</head>
<body>
<div class="myDiv">
<button>myText</button>
</div>
<div class="myDiv">
<button>myText1</button>
</div>
<div class="myDiv">
<button>myText</button>
</div>
</body>
</html>