The claim is a little disingenuous, because it introduces a false equivalence between
After all, anyone can conduct an investigation (below you will see mention of "bounty hunters" running their own); investigations might not be publicly disclosed; the existence of an investigation is not an indication of wrong-doing, especially when they are politically motivated.
Nonetheless, it is true that the Clinton Foundation has been the subject of some investigations instigated by Republicans.
John W. Huber is the US Attorney for the District of Utah. He has been leading an investigation involving the Clinton Foundation since November 2017. The Salt Lake Tribune reports
Huber had been assigned by then-Attorney General Jeff Sessions to investigate several controversies Republicans have raised about Hillary Clinton and the Clinton Foundation, many of them stoked by right-wing activists who believe she should be prosecuted.
In addition, the House Oversight Committee, lead by Rep. Mark Meadow has recently held hearings.
Hillary Clinton haters were all a-flutter about the prospect of “explosive” information being revealed at Thursday’s hearing on the Clinton Foundation as the last hurrah from Rep. Mark Meadow’s (R-NC) chairmanship of the House Oversight Committee. The first blow to their expectations came when U.S. Attorney John Huber, who was tasked by former Attorney General Sessions to investigate all of the anti-FBI conspiracy theories germinated by right wingers, announced that he would be a no-show.
However, Meadows proceeded with the hearing anyway after having lined up witnesses like Tom Fitton, president of Judicial Watch, and two men who have been described as both “whistleblowers” and “bounty hunters.” Fitton performed as expected, given his organization’s ongoing attacks on everything related to the Clintons. The real anticipation was over the testimony of the bounty hunters who claim to have spent three years doing forensic financial analysis of the Clinton Foundation.