Konstantin Yuryevich Nikolaev ... is a Russian billionaire and businessman who is a financial supporter of Maria Butina, a co-owner of the Tula Cartridge Plant that supplies very large amounts of ammunition to Russian forces during Russia-Ukraine War, American Ethane, N-Trans and Globaltrans, the largest private rail operator in Russia, CIS, and the Baltic states. He is only under sanctions by Ukraine. According to the Forbes, in 2019 Nikolaev's net worth was estimated at $1.2 billion.
Through Igor Levitin, Alexey Mordashov, Arkady Rotenberg, Gennady Timchenko, and Alexander Voloshin, Nikolaev is a partner and close associate of numerous persons in Vladimir Putin's inner circle.
...
His son Andrey Nikolaev ... lived in the United States as a student at Columbia University in New York City during 2016 and was a volunteer at Donald Trump's headquarters during his Presidential Campaign in 2016. While at Columbia University, Andrey Nikolaev was very active as a leader in the university's Republican (GOP) community who met with Mike Cernovich.
https://en.wikipedia.org/wiki/Konstantin_Nikolaev
Only sanctioned by Ukraine, heavily involved in various Russian sanctions-busting initiatives since 2014.
Mikhail Yuryev died in 2019, so that info's out of date, and in the wrong tense anyway, as is the whole tweet, because
Newsweek's only talking about donations to Johnson from 2018. He did found American Ethane with former Kremlin Chief of Staff Alexander Voloshin and was a major shareholder at the time of the donations.
Andrey Kunatbaev seems a relatively minor player compared to Nikolaev, having served in the Duma.
I'm sure this is just the tip of the iceberg. There are many, many other links involving Republicans once you go digging, such as this from 2019:
Former Trump campaign aides are now lobbying for a gas company part-owned by Putin's former chief of staff
* Former aides to Donald Trump's 2016 presidential campaign have been hired to lobby for a Russian-owned ethane company.
* American Ethane Company is one of the largest gas companies of its kind, and is partially owned by multiple billionaires with ties to Russian President Vladimir Putin.
* The lobbying group is called Turnberry Solutions, which shares a name with Trump's golf course in Scotland.
https://www.businessinsider.com/former-trump-campaign-aides-lobbying-for-gas-company-backed-by-russians-2019-2?r=US&IR=T