Misschief is right. Even if you make your own hydrosol rather than buy it, I wouldn't waste it in soap.
As I said in your other thread, diluting with hydrosol is a safety concern if you don't use an effective preservative.
If you use hydrosol to make the soap paste, the scent won't survive the lye. New soapers think teas and infusions will scent soap, but usually there is no scent or sometimes only the barest trace of scent left after saponification, even if a concentrated infusion is used.