how export groups are working?

[SiriVFX]

i try to export particles in different groups, to apply different material after that.
but if i use global export(export node in a single event) it seems to export every visible particle.
thought i turn on export group A in display node and export node it would only export all A marked particles.
but the particle disappear when i select a a group in the display node.

if i put the node in an event it exports only the particle in that event.

and i also dont know what this overlapping/equal/not equal does.

[tyFlow]

You have to assign groups with a Particle Group operator. The group checkboxes in other operators then filter out particles based on your assignments.

[SiriVFX]

but what effect or purpose has the tyActor Property than, where i can set export groups too.
same with export group at the display node.

[tyFlow]

If you assign tyActor properties to geometry, tyFlow will import those properties and assign them to the corresponding particles. In that case you wouldn't need a Particle Group operator.