This article talks about an open-source RSS reader with search filters, article structure, and more. When it comes to RSS reader there are plenty of options you can go with. There are free as well as paid services and apps that give you full control over your feeds. If you are looking for a free and feature-rich RSS read then here is one that you can try.
Fluent Reader is a modern UI inspired RSS reader desktop app that brings all your RSS feeds together. Where most of the RSS reader shows you a simplified version of web articles, this one can show the actual article structure with options to change the font and easy sharing with QR code. It also allows you to enter multiple terms in the search bar to create search filters and list specific feeds. Apart from that, you get all the features that you can expect from an RSS reader including, dark theme, keyboard shortcuts, groups, and custom source rules. You can import data from your existing reader via an OPML file. You can also backup and restore the data of this reader at any given time.