Tax Return advice: 5% of your Child Care Subsidy claim?

Govt withhold 5% of your Child Care Subsidy each fortnight to reduce the likelihood of an overpayment.

1) In which section of form of tax returns we have to complete the info to get those 5% back?

2) Also, I think I might have missed it to claim in last year's tax returns. Is there any way now to check if I forgot it last year? And is it possible to claim it now?

TIA guys