multiple extensions with EditorUtility.OpenFilePanel

I want to use EditorUtility.OpenFilePanel to open Exel files, but it contains only one extension parameter and I would like to open .xls and .xlsx files. I have tried a lot of different things like “xls;xlsx”, “.xls;.xlsx”, “xls|xlsx”, … but they all failed. So is it possible with this function to filiter multi extensions? And if yes how can I do it ?


I’ve yet to find a solution for this myself, the “xls;*.xlsx;” did not work for me.

Has anyone had any luck with this?