Many of the settings are identical to xpBullet Rigid Body and illustrations for them can be found in that page.
In order to test for collision between a particle and a scene object, the scene object must have an instance of this tag attached to it.
Particles can collide with splines as well as polygon objects; you don't need to add any geometry, just a primitive or editable spline itself is sufficient.
In this animation, a Cube represents the floor, with an xpBullet Collider tag attached. This is creating dynamic collisions for the Capsule (with an xpBullet Rigid Body tag), the Torus (with an xpBullet Soft Body tag) and the particles (the xpEmitter has an xpBullet Rigid Body tag).
xpBullet Collider tag Dynamics tab menu settings.