Set Event A group to '1,2'
Set Event B group to '2,3'
Use a Flock operator or a Particle Physics operator (with 'integrate' turned off and 'affect' set to velocity) to do the attract/repel.
Set Flock/Particle Physics group to 'Not Equal to Own'.
They will all collide with each other within the PhysX engine because they have overlapping groups, but only particles from opposing events will collide/attract (ie, particles whose group is not identical to their own).
Attached is a scene file you can reference.
Set Event B group to '2,3'
Use a Flock operator or a Particle Physics operator (with 'integrate' turned off and 'affect' set to velocity) to do the attract/repel.
Set Flock/Particle Physics group to 'Not Equal to Own'.
They will all collide with each other within the PhysX engine because they have overlapping groups, but only particles from opposing events will collide/attract (ie, particles whose group is not identical to their own).
Attached is a scene file you can reference.