How exactly does the party experience share bonus work? Party experience share requirements:
Party share experience is enabled
To take part of the shared experience and the bonus, you must have dealt at least 5% damage to the monster.
Every member must be at least Level: (x * 2) / 3, where x is the highest level in the party.
An example: if the player with highest Level in the party is Level 50, the members of the party must be at least Level (50 * 2) / 3, which is 33.3333... and rounds up to 34.
The experience will be divided by all members who have dealt enough damage to the monster, and these member will also receive an additional 40% experience bonus. Both the shared experience and the bonus experience is multiplied with the multiplier of your current experience stage.