This is the 11209th most frequent Russian word.
групповыми
The Russian word "групповыми" means "group" or "collective" (instrumental plural form).
In this sentence, "групповыми" is used as an adjective in the instrumental plural form to describe the type of activities as being group-based.
Мы проводим встречи с участниками групповыми занятиями.
We hold meetings with participants at group activities.
Here, "групповыми" is again an adjective in the instrumental plural form, indicating that the sports being referred to are group-oriented.
Она увлеклась групповыми видами спорта.
She became interested in group sports.
In this instance, "групповыми" is used to describe the efforts as collective or group-based, maintaining the instrumental plural adjective form.