Using SQL Developer 4, you can initiate the data pump export or import job. It has export wizard under the menu view -> DBA. Using this you don’t need to aware about the data pump options to invoke a data pump job. All those data pump options can be invoked through the wizard. Here I will show you an example for one export job.
Invoke the export wizard using menu view -> DBA
Click on the Export Jobs -> Actions in the right pane -> Data Pump export wizard
In the first step you have to specify the database connection, data/ddl (Metadata Option), whether you want full db, schema, tablespace wise, table export etc.
Type the name of the object/schema which you wanted to export and press on the lookup button. Add those objects to the right pane by clicking right arrow.
Here you can specify the where clause (Query Parameter) if you wanted to filter it out some data.
Here you have to specify whether you want a logfile and consistent backup (Flashback SCN Parameter) also.
In this step you have to specify whether you wanted to overwrite the dump file or not which is equivalent to reuse dumpfile parameter. Then you go to summary page and finish. If you wanted to schedule the job for some other date or time, that is also possible.Normally the dump file will go to the data_pump_dir directory.