如何在搜索时忽略unicode字符？

I'm trying to implement searching for my app. If You write an exact word in the search bar, it's ok but for example if I want to find "book" and I type in "böök"diacritics shouldn't matter. I was using the code below but it's not useful and also fails while searching e.g "New York - Björk". I also tried different combinations of searchEditedText but the code became disgusting. How can I do that? I'm trying to implement searching for my app. I