I never use that dropdown menu with the different file types, it just requires another extra action whenever i use the filter. Therefore i would like to suggest an option to save the "enter" key press to get into the list of filtered items.
Do you mean you want to use Enter to open the menu instead of clicking with the mouse?
F4 will open the drop-down/menu when a combobox like that has focus. (This works almost everywhere, not just in Opus or the filter bar.)
The Enter key already does something here: It applies the filter and returns focus to the file display.
I want to be able to move the cursor keys, with no Enter beforehand, no combobox needed, right after i've entered the search word. That would speed up the whole action. Because mostly i filter in large music lists, where the type (mostly MP3) doesn't matter anyway. That could be a nice addition to the miscellaneos section.
edit, removed the first line