Group finder is just a tool that displays other players and their skill level who are looking to do content in groups. It can show what content they want to do, allowing the players to make communication with each other from there on. An example of this is when I log in and want to hunt or kill monsters,I look on the group finder to search for players wanting to do combat/hunt missions at the same skill/level as me. Just a basic feature of what some other games have.
