I think the line is whether the source is...

Giuliani did not say whether he knew about the recordings before their release or worked with Derkach to ensure they became public, saying attention should be focused on Biden. “Just the tip of iceberg,” he wrote in a text.

Via @paulsonne @postroz:https://t.co/ObROn5V9Im

— Matea Gold (@mateagold) May 20, 2020

....foreign or domestic.

You wouldn't know it from that tweet, but the article is very dismissive of the tapes that were released:

A Ukrainian lawmaker who met with Rudolph W. Giuliani late last year released recordings of private phone calls between former vice president Joe Biden and former Ukrainian president Petro Poroshenko in a new broadside against the presumptive Democratic nominee for U.S. president that has raised questions about foreign interference in the 2020 election.

In composition that's what's known as the "introductory paragraph."  It lays out the themes/topics the essay (in this case news article) will cover.  So the tape release is a "broadside" against Biden "that has raised questions about foreign interference in the 2020 elections."  Nothing wrong with that, actually, but considering how much bullshit spews from the mouth of Donald Trump and how much of it is treated as words which must be taken as true, it's a bit curious to see this in a news article about politics.

I wish the media would stop saying, “Trump is taking the drug” and instead say, “Trump CLAIMS he’s taking the drug.” To believe he’s taking hydroxychloriquine I’d need to see a livestream of Rep. Pelosi opening a sealed bottle of the drug and feeding it to Trump like a baby bird.

— Glenn Kirschner (@glennkirschner2) May 19, 2020

Moving on:

Andriy Derkach, an independent member of Ukraine’s parliament who previously aligned with a pro-Russian faction, said at a news conference in Kyiv on Tuesday that he had received the tapes — which consist of edited fragments of phone conversations Biden and Poroshenko had while still in office — from “investigative journalists.” He alleged they were made by Poroshenko.

Pretty clear what the point of that paragraph is.  But why can't reporters say "Donald Trump, a man who has made 18,000 documented lies in his three years in office, asserted today that he takes a drug the FDA restricts to clinical trials and hospital settings only for any effort to treat coronavirus"?  Asking for a friend.

Derkach has past links to Russian intelligence. He attended the Dzerzhinsky Higher School of the KGB in Moscow. His father served as a KGB officer for decades before becoming head of independent Ukraine’s intelligence service in the late 1990s. His father was fired from that post amid a scandal over a Ukrainian journalist who was kidnapped and murdered.

This is good.  Trump also has links to Russia, is a serial liar, and had to shut down a charity due to his fraud.  Might be worthwhile to mention that once in a while, huh?  Speaking of edited, I'm going to edit a few more excerpts from this article:

The recordings played at the news conference Tuesday shed relatively little new light on Biden’s actions in Ukraine, which were at the center of President Trump’s impeachment last year. They show that Biden, as he has previously said publicly, linked loan guarantees for Ukraine to the ouster of the country’s prosecutor general in 2015. But Derkach used the new clips to make an array of accusations not proven by the tapes.

No more proven than Trump's assertions that hydroxychloroquine is safe and the VA is full of his enemies?

The events have echoes of the 2016 presidential election, when Russian operatives hacked and released emails from the campaign manager of Democratic nominee Hillary Clinton and officials at the Democratic National Committee, in what U.S. intelligence agencies later concluded was a Moscow-directed operation designed to boost Trump.
....
Nearly four years later, Trump’s eldest son is blasting leaked information of unknown provenance from a Ukrainian lawmaker about his father’s rival in the 2020 election. Trump Jr.’s tweet linked to a YouTube page with a recording that was also packaged with English subtitles.
....
The tapes released in Kyiv offered no evidence to back Giuliani’s long-standing accusation that Biden pushed for the prosecutor general’s ouster to help his son. 

Like I say, nothing wrong with this reporting.  I just don't understand why reporters can be so skeptical of foreign sources, but so gullible when the source is domestic.  Maybe it has something to do with American exceptionalism.