To Use the Drag-and-Drop Operation to Select Models for Batch Processing from Properties Dialog

Open the Properties dialog ( Drawing > Home > Primary > Properties ).
Do one of the following:

In the File tab of Properties dialog, select the model that you want to process.

or
Press and hold down the <Ctrl> key, then select multiple models.
Drag the selected files to the Process Tasks list in the Batch Process dialog, releasing the <Ctrl> key to complete the task.
If you want the files to be dropped between two existing processing tasks, position the pointer between them prior to dropping the files.