This is the 908th most frequent Polish word.
grupę
The Polish word "grupę" means "group" (accusative/singular form).
Here, 'grupę' operates as the direct object of the sentence, indicating a collective noun for friends as the receiver of the action.
Spotkałem grupę przyjaciół w parku.
I met a group of friends in the park.
In this case, 'grupę' is used to describe a group as a collection of animals and serves as the direct object.
Grupę zwierząt widziano w lesie.
A group of animals was seen in the forest.
'Grupę' in this sentence refers to a particular group located at the beach and functions as the object of the verb 'zauważyłeś' (did you notice).