The phrase "two groups of friends" is correct and can be used in written English.
It is typically used to refer to two separate sets of people who are friends with each other. Example: Tina had two groups of friends - her childhood friends from her hometown and her college friends.
Police believe the man died after a fracas involving two groups of friends at about 5.15am.
The two groups of friends had got to know each other in South America and began travelling together.
The teenager found he now had two groups of friends – his Cardiff pals and online colleagues from the increasingly well-organised sceptical community.
Of course, Mr. Gore is the product of both Washington and Tennessee -- and of the very fact of having grown up in two places, with two groups of friends and two ways of looking at the world.
The brawl began inside the Metropolis in College Point, where members of two groups of friends, "an upper crust" group from Whitestone and a working-class group from Howard Beach, got into a shoving match, according to testimony and prosecutors.
Two men from Queens were killed early yesterday after a fight between two groups of friends spilled out of a social club and onto the street, the police said.
For example, let's say your two group of friends are standing relatively near each other.
Some are "compartmentalizers," with two to four groups of friends where friends know each other within groups but not across them.
On a frigid night last month, three groups of friends took turns knocking through twangy covers of the usual suspects: The-Dream, Bone Thugs-n-Harmony, the Cardigans.
So Groupers consist of two groups of three friends, three guys and three girls, three girls and three girls, three guys and three guys, three cats and three dogs, etc. (Not the last one).
People now turn to one group of friends for financial advice and another for political or spiritual discussions, for instance.
