Hi Abrar,
From what I understand from your question, I assume that all parameters are string, then the easiest way is to start with an empty check validation, either one by one or all-in one decision for example
(Parameter1 != empty and Parameter1 != '') and
(Parameter2 != empty and Parameter2 != '') and ...etc
After this decision true goes to the retrieve action by xpath where xpath looks like;
Object/Atribute1 = $Parameter! and
Object/Attribute2 = $Parameter2 ... etc
and false goes to retrieve action of the object without any constrainst.
I hope this works for you,
Ferhat