You can view the message feed not only in topic mode but also in tag mode. Switch to the tags tab to do this.
Viewing a single tag
To view the feed by a specific tag, press the tab with the tag name.
By default, switching between tags clears the filters on the right-hand side of the screen.
To switch between the tags while keeping the filters in place, tap the filters icon on the tag name bar
View more than one tag
To select more than one tags to view, click the checkbox to the left of the desired tags in the right-hand menu and the OK button at the bottom of the list of topics.
By default, multiple tag selection means that all documents that contain at least one of the selected tags will be listed in the message feed.
You can also view the list of documents that contain all the selected tags at the same time. To do so, switch the type of results displayed at the top of the tag column.