You can copy (duplicate or clone) a parser from the parser list page. To reach the list of all parsers you can click on the Docparser logo in the top left corner. Then, hover your mouse over the parser you want to copy and click the Duplicate Document Parser icon:
List View
Panel View
Alternatively, you can also copy individual parsing rules (or layout models) from one parser to another:
Another option to copy a Parser is within the Parser Settings: