See also: BranchID, VariableID
Returns the unique branch
ID associated with the parent of the current branch of the branch specified
in the branch:variable reference. This function can be useful when
you need to pass information about the LEAP tree structure to an external
script or DLL.
When used with no parameters the function returns the ID of immediate parent branch or the current branch. When used with the levels parameter, the function returns the parent (levels=1), grandparent (levels=2) etc.
Note that when levels are set to zero the function is equivalent to the BranchID function (i.e. it returns the ID of referenced branch).
ParentID(Demand\Household\Refrigeration:Activity Level, 2) = 1 (the ID of the Demand branch)