Hola de nuevo.
Prueba este código, a ver si te en entendido bien:
Código PHP:
<html>
<head>
<script>
function ver(txt) {
filas=document.getElementById('tabla').getElementsByTagName('tr');
for(i=0;i<filas.length;i++)
filas[i].style.display=(filas[i].getElementsByTagName('td')[0].innerHTML==txt)?'block':'none';
}
</script>
</head>
<body>
<table width="75%" border="1" id="tabla">
<tr>
<td>1</td>
<td>1-2</td>
</tr>
<tr>
<td>2</td>
<td>2-2</td>
</tr>
<tr>
<td>1</td>
<td>3-2</td>
</tr>
<tr>
<td>3</td>
<td>4-2</td>
</tr>
<tr>
<td>1</td>
<td>5-2</td>
</tr>
<tr>
<td>2</td>
<td>6-2</td>
</tr>
</table>
<select onchange="ver(this.value)">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
</body>
</html>
Saludos,
