Is it possible to edit/add the predifined fields?

Is it possible to edit/add the predifined fields?

In Zoho Campaign, list management, is it possible to edit and to add personalised fields in the Segment Criteria fields? 
We have created lists divided by countries but within those countries we would like to be able to segment for example profession and status of candidates, but those fields (the ones we need) do not appear in the Segment Criteria list.
Is it possible to add them? 
thank you