This set of actions does, as it only was meant as a general suggestion for you or others to build on.
Create a new shortcut
Optionally add Ask for Input action
Add Find Items action
? and set the search scope (optionally change query to manual input)
Add Choose from List action
Add DTTG Create Item action and set location to output of Choose from List action
What your specific situation requires is obviously impossible to guess from your initial information, but you can setup Shortcuts to let you choose from a certain location and use that location to create a document.
It might be you need to change your database organization to narrow down the search query in step 4 as the wildcard
? will output all items and that might result in a large list of possible locations. But if you happen to have a group called Projects that contains projects by reference numbers, you might search for a specific number in optional step 2 or setup menus in Shortcuts. Be creative and you’ll undoubtedly find a way