The tokens for userroles are only available in Xpath retrieves, this is a regular microflow expression. And the brackets you use are only used in Xpaths, not here.
So first do a retrieve of a userrole object where ID = userrole_token. Then you can do an exclusive split to check if the association from currentuser to userrole matches that object.
You are using an XPath expression in an exclusive split.
I had the same kind of issue. But I had to check if the user had a certain role. This is what I did to solve it.
Hope this helps for in the future!