Currently in the Library screen the sort in the defult library only operates on author. As a result, publications of any particular author are not in year order.
My suggestion is in two parts
add a check box to the sort order specified in the dialog box under the Tools / Sort Library submenu, that sorts the library view items
use the selected sort order in the dialog box under the Tools / Sort Library submenu
Curently the multi-field sort order in Tools submenu only works when a sort is executed. The check box in the dialog box is needed to make it apply to the Library view screen
You can go to the tools menu and choose sort - this lets you sort by up to 5 criteria. Is this what you are looking for?
On a side note, I would like Endnote to remember sorting preferences for each group. Eg. I could have a group for papers by a particular author that will always sort by year whereas my main library sorts by author.