Since I was helped with my project by the answer above (I asked a duplicate question and was referred here), I am submitting an answer (my test code) for bracket notation when nesting within the var:
<html>_x000D_
<head>_x000D_
<script type="text/javascript">_x000D_
function displayFile(whatOption, whatColor) {_x000D_
var Test01 = {_x000D_
rectangle: {_x000D_
red: "RectangleRedFile",_x000D_
blue: "RectangleBlueFile"_x000D_
},_x000D_
square: {_x000D_
red: "SquareRedFile",_x000D_
blue: "SquareBlueFile"_x000D_
}_x000D_
};_x000D_
var filename = Test01[whatOption][whatColor];_x000D_
alert(filename);_x000D_
}_x000D_
</script>_x000D_
</head>_x000D_
<body>_x000D_
<p onclick="displayFile('rectangle', 'red')">[ Rec Red ]</p>_x000D_
<br/>_x000D_
<p onclick="displayFile('square', 'blue')">[ Sq Blue ]</p>_x000D_
<br/>_x000D_
<p onclick="displayFile('square', 'red')">[ Sq Red ]</p>_x000D_
</body>_x000D_
</html>
_x000D_