Capacitor Voltage Rating
If the input voltage is 60 V, then a capacitor connected between the input and ground must be rated for at least 60 V, regardless of what capacitance it has. 

If the output voltage is 5 V, then a capacitor connected between the output and ground must be rated for at least 5 V, regardless of what capacitance it has.

And of course it should actually be rated higher, in case the applied voltage varies, or there's a transient voltage applied. Some capacitor types will reduce in value as the applied voltage approaches the rating, perhaps by as much as 85%. Some capacitor types will have "recommended derating" information that might recommend using a capacitor rated for twice the actual applied voltage. Be sure to read the datasheets for any capacitors you're considering using to know whether they're appropriate for your circuit.