If you want to clear a edit record you need to create a record variable of same type and assign it to the widget.

If you want to clear a list records or table records you have to create a list variable of same type and assign it to table records list.

What you could do is create a record : ContactEmpty.

If you want to clear the form, instead of assigning each variable individualy, you could do : 

Contact = ContactEmpty

(the variable your form is binded with)

If you have many filters on a screen instead of creating several variables, create a structure and then you can clear it like a record

Hi All,

Select the designation source to current screen and pass the input parameter to NullIdentifier() to that screen.

This will clear form elements in the screen.

You can clean the Structure easily by just following these steps:

1. Create a client action with a local variable of the same data type as the Structure you want.
2. Add an assignment on clear client action. In the Variable field, add the Structure you want to clear, and in the Value field, select the local variable from the same client action.

This way, you can use it wherever you want.
For Example: