Officers were called to Millers Barn, Nuthall, after a brawl involving multiple people happened in the beer garden.
Three people wearing face coverings reportedly ran over and started the assault, around 6.55pm on Friday, May 10.
The suspects were reportedly seen brandishing a machete and shovels during the incident.
A man was left with cuts to his hands following the assault, while another man sustained a blow to the back of the head.
Following the incident, the individuals with the weapons were seen to jump over a fence and get into a car before driving away.
Police investigating the incident have now launched an appeal urging anyone who saw what happened to come forward.
Det Insp James Oakton, of Nottinghamshire Police, said: “This was a nasty attack that will have been seen by multiple people, due to the time and location it took place.
“What with it being a nice sunny evening, the pub garden in question was full of families who sadly had to witness what must have been a very alarming sight.
“We stepped up visible police patrols in the area over the weekend to provide the public with some reassurance and this will continue in the coming days.
“It really should go without saying but the violence demonstrated in this incident was completely unacceptable, so we’re determined to track down the people responsible.
“To anyone who saw what happened or has any information that could help us do this, I’d ask that they report it immediately.
“This can be done by calling the police on 101, quoting incident 711 of 10 May 2024, or by contacting Crimestoppers anonymously on 0800 555111.”