Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Freeze
FIELDLAYER_PROXIMITY_FORCE_SAVE
Parameter: Clear
FIELDLAYER_PROXIMITY_FORCE_CLEAR
Parameter: Mode
FIELDLAYER_PROXIMITY_MODE
Parameter: Auto-Update
FIELDLAYER_PROXIMITY_DYNAMIC_UPDATE
Parameter: Subfields Only
FIELDLAYER_PROXIMITY_SELF_AGGREGATE
Parameter: Optimize Search Tree
FIELDLAYER_PROXIMITY_USE_INPUT_CRC
Parameter: Radius
FIELDLAYER_PROXIMITY_RADIUS
Parameter: Effect Strength
FIELDLAYER_PROXIMITY_EFFECT_RATIO
Parameter: Radius
FIELDLAYER_PROXIMITY_FIELDS