Fixed expenses folders/categories

I would like to mark some folders/categories as fixed expenses (and add them manually). I have now setup a folder ‘fixed expenses’ with various categories ‘mortage’, ‘insurance’ etc. I would like to add fixed expenses manually (amount may not always be the same + monthly date of transaction may not be the same). Rather then setting individual items as fixed expenses, I would like to set the entire folder/category as fixed expenses for any transaction added to them.