Not seeing serial number: No able to see the serial number in the Manage Item Quantities

You can do is as below 

 Query item which you want to view serial > navigate to the sub inventory and below serial number will highlight, and click on the below Query by Example

Query by Example for Serial Numbers on the Manage Item Quantities Page

You can quickly search for serial number information on the Manage Item Quantities page by using the Query by Example functionality.

1. From the Inventory Management work area, select the Manage Item Quantities task.
2. Search for an item.
3. Select the Serial Number Details tab.
4. Click the Query by Example icon in the toolbar to enable the Query by Example search framework.

   A blank filter row appears immediately above the Serial Number column. Use this row to filter your serial numbers.

5. Search for your specific serial number or a group of serial numbers by entering a partial or complete serial number in the filter row and pressing Enter.

   Serial numbers matching the serial number or partial serial number you entered display.