Number of child for a Profile Communities run on an entity is governed by the policy attribute “Correlation Direction” in the Profile Communities Basic Configuration policy.
If Correlation Direction is
UNI = 2 children per entity for lead and lag signature
BI = 1 child per entity for cooccurrence signature
BOTH = 3 children per entity for lead, lag and cooccurrence signature
Any other value = NO child will be created
Please note that comma separated values are also not supported here.