p:dataTable filteredValue attribute

I'm using p:dataTable to display a table of data. I've used the attribute "filteredValue" hoping to obtain the filtered data in p:dataTable.

I've added a button called print, it's purpose is to display the filtered table data in another blank page. The button has a method, which is in the same bean. It looks like this.

action = "#{beanname.method(beanname)}"

The issue I'm having is the bean property which the attribute "filteredValue" is setting (a list , beanname.filteredList ) is null.

It would be great if anyone here has an idea about this problem. Appreciate the help.