Although this is an older post, this may still help people who are searching for the same answer.
This functionality is now available in standard Microsoft Dynamics 365 Business Central. At least from Business Central version 27, the Item Ledger Entries page includes the field Source Order No., which shows the related order number for the entry.
You may need to add the field to the page using Personalize if it is not visible by default.
So, in current versions, no customization should be required for this requirement, provided the relevant source document information is available on the entry.
