Unable To Filter Collection

I was trying to filter Collection Based on Date and If I am giving Hard-Coded Values Then It is working
Example:
[Collection: Example]
Parm Var:SVFromDate : Date : "01-01-18"
Parm Var:SVtoDate: Date : "01-01-20"
Type: Voucher
Fetch: Date

You can check this it is working But If I change SVToDate Parameter To SVFromDate Then It stopped working
Example:
[Collection: Example]
Parm Var:SVFromDate : Date : "01-01-18"
Parm Var:SVtoDate: Date : ##SVFromDate
Type: Voucher
Fetch: Date

 

Already Tried and After Some Research This method worked

[Collection: Example]
Parm Var:SVFromDate : Date : "01-01-18"
Parm Var:SVtoDate: Date : #SVFromDate -1
Type: Voucher
Fetch: Date

And Thank you Very much for your response