I just put up my new website including a first blog post about FileMaker portal filtering & window variables!
In this post, I present a "universal" script for portal filtering. A sample file is included.
While building this file, I wanted to demonstrate how one could have different portal filters in different windows, even if the layout & record was the same. Although I figured out a workaround to make this work, I noticed what I believe is a bug. More on that here: Refresh Portal can break filter on same portal in other open windows (also note: the sample file included in the bug post is a simplified version of the one available from my blog, in order to show the bug clearly).
Hope this post is useful to someone! Any feedback of all kinds is very welcome and I'd love to have those conversations both here as well as in the comments on my new site!;-)