For each table you're exporting you'll need to add a filter like:
dbms_datapump.data_filter ( ... , value => 'WHERE insert_date >= date''2020-01-01'' and insert_date < date''2021-01-01''' );
This assumes all the tables have a column named insert_date storing when the row was added. Adjust to match the columns in your schema.
If there are tables without this (or a similar) column... you're going to struggle!
Bear in mind that there may also be rows inserted in earlier years that you need for referential integrity. For example, you can have orders made last year for customers first inserted many years ago. How you resolve this kinda depends on why you're trying to do this.