On every document and journal that can be posted, you can choose the Preview Posting button to review the different types of entries that will be created when you post the document or journal.
Below I have shown Example from Sales Invoice Window, similarly you will get in other related Pages too.
From Actions TAB you will get this option for Preview Posting.
You will get below Navigation Window where you can Navigate Entries which will get posted upon Posting.
Give it a try, very useful feature introduced in Navision 2016.