Anita75,
Happy New Year. First an general overview of the Revaluation Journal...
There are typically two scenarios regarding inventory revaluing. In the first scenario, you would want to revalue all of the remaining quantity in inventory for an item. In the second scenario, you would want to revalue a single increase to inventory (positive adjustment, for instance). This scenario could be caused by an incorrect cost posted in a Dynamics NAV Item Journal in which that inventory has already been deducted from inventory. When you do run the Revaluation Journal, in both scenarios, you will notice Applies-To Entry column, which links the Revaluation Amount to the Open Item Ledger Entry being adjusted. However, you can run the Revaluation Journal and Calculate Per Item. This will apply the Revaluation Unit Cost to all Open Entries (see example below).


In either case, in the end, each FIFO or LIFO layer, depending on which Costing Method (Note: Average and Standard do not use this journal), all Open layers will be updated and posted too.
Just a note, you must run Adjust Cost - Item Entries prior to running the revaluation journal as my colleagues noted. You can run setup Automatic Cost Adjustment on the Inventory Setup page.
I hope this helps explain the Revaluation Journal and how it posts.
Thanks,
Steve