This article mentions Blindspotter, which is a great way to explore the bubbles around Twitter accounts (https://ground.news/blindspotter/twitter) and also Subreddits (https://ground.news/blindspotter/reddit/). For example, try:

John Oliver - https://ground.news/blindspotter/twitter/iamjohnoliver

Tucker Carlson - https://ground.news/blindspotter/twitter/TuckerCarlson

r/politics - https://ground.news/blindspotter/reddit/politics

r/moderatepolitics - https://ground.news/blindspotter/reddit/moderatepolitics

r/conservative - https://ground.news/blindspotter/reddit/conservative

BTW Blindspotter is built by Ground News (https://ground.news/). They're like All Sides (https://www.allsides.com/) in that they provide displays that let you see articles from across the spectrum on a given story. But they also measure how much of a blindspot there is for the left or right based on how heavy or sparse the coverage of a story is from news sources of various biases, since much of the time we're not dealing with biased articles as much as selective coverage.