I am using Version 5.18.2 (Build 518.35919.100) on OSX El Capitan.
The budget display opens with all the income and expense categories expanded, i.e the subcategories are shown. The resulting display is too large and complex for me to comprehend so I normally go through and close them. This allows me to proceed from the simple to the comprehensive when I see a need to do so, i.e. if a category is "out of whack" I expand that category to find out why and I close it once I've resolved the issue.
And of course if you leave the budget to work on an account register when you return to budgeting again there expanded once more
I don't believe there is a setting which allows this. If there is please point me to it.
I understand that others may have a different opinion, but the option do either in a future release would be a good solution.
[Edited title for clarity and discoverability - @jacobs 7/12/21]