The crew in the helicopter could not focus on an ADS-B In display as they didn't have one. However, if they had one, they could have glanced at the ADS-B In display to see which aircraft the ATC was referring to and to compare that position to the outside. They would know the airliner was very close and crossing just ahead of them. There was no need to check altitude as they knew the other plane was on final and they were not trying to scoot under it.
The following video is from NTSB, about 8 years ago concerning the midair collision between Cessna 150M, N3601V and Lockheed Martin F-16CM, 96-0085
From the description:
A reconstruction of the airborne traffic information that could have been provided by Cockpit Display of Traffic Information (CDTI) equipment, had it been available, is displayed in the upper left corner of the screen. The animation also recreates the aural traffic alerts that would accompany the graphical presentation of these alerts on the CDTI.