William,
Savings’ concept of budget is different from some other finance apps in that it emphasises budgeting for all categories, and ideally for the whole year, so you can see how much you will actually save in a year. This is why there is no option to make a budget only for a select set of categories.
However, you may workaround this by just setting all the categories you don’t want to budget to a budget amount of zero, then they will always be sorted to the bottom of the list. Does that work?
Actually, I am interested to know why you would want to budget only a certain set of categories. Isn’t the whole picture more important?
Yi