Filter selected elements by Category & Comments (or by a instance parameter)

Hi everyone, I just try to learn Dynamo recently, sorry if it is a dump question! I try to filter out from selected elements by catergory and then by Comments using Filter by BoolMask, after it is working for the first one (filter by structural columns), I try to use the result to filter by boolmask again but it is not working, please let me know how to correct it, thanks heaps

Hi Jeff,

Thanks for your reply but where can I get the “Element.Category” Note