Within the Inventory module you can create multiple warehouse locations yo house your stock. If you need to reallocate stock from one warehouse to another this can be achieved by creating and booking an Inventory relocation entry.
Go to Inventory > Inventory books > Inventory relocation.
Click on the New Inventory relocation line option.
A window will appear where you will have to define the different fields to report the change that is being made:-
Product number - select the product to be relocated
Quantity - enter the quantity concerned
Select the location you are transferring from an the location you are transferring to
Your draft entry will be listed, select the entry and click book relocations.