Is it possible to make changes to the SubList "Locations" on the item card under the tab Purchasing/Inventory?

Not that I have found. You can make a saved search with the same data and be able to add fields that way and set it as a sublist to replace that one.

You should be able to edit the from then click Move Elements Between Subtabs Then there will be a "Lists" subtab Somewhere in there will be Locations, you can choose the subtab you'd like to move it to then save that screen, and save the form.

So I think what you are saying is that I create a new subtab and put a new list under that subtab. Unless there is a way to add another sub-list onto the Purchasing/Inventory page. If there is, I have not found it.

@AmyBecker I'm sorry - I read your question wrong. I thought you were trying to move the Locations sublist under the Purchasing/Inventory tab. @Zack is correct - you cannot make changes to that sublist. But you can recreate it in a saved search and then add that search as a Custom Sublist to the Item form