Converting List Attributes from 3D CityDB to CityGML Using FME

I solved it with a PythonCaller. Way easier to handle the data there.

Here is the Python code if anyone is facing the same problem:
 

import fme
import fmeobjects

class FeatureProcessor(object):

    def __init__(self):
        pass

    def input(self, feature):

        function = feature.getAttribute('function')
        function_codespace = feature.getAttribute('function_codespace')
        usage = feature.getAttribute('usage')
        usage_codespace = feature.getAttribute('usage_codespace')

        function_list = function.split('--/\\--')
        function_codespace_list = function_codespace.split('--/\\--')
        usage_list = usage.split('--/\\--')
        usage_codespace_list = usage_codespace.split('--/\\--')

        for i, value in enumerate(function_list):
            if value:
                feature.setAttribute(f'citygml_function{{{i}}}', value)

        for i, value in enumerate(function_codespace_list):
            if value:
                feature.setAttribute(f'citygml_function{{{i}}}.codeSpace', value)

        for i, value in enumerate(usage_list):
            if value:
                feature.setAttribute(f'citygml_usage{{{i}}}', value)

        for i, value in enumerate(usage_codespace_list):
            if value:
                feature.setAttribute(f'citygml_usage{{{i}}}.codeSpace', value)

        self.pyoutput(feature)

    def close(self):
        pass

    def process_group(self):
        pass

    def has_support_for(self, support_type):
        if support_type == fmeobjects.FME_SUPPORT_FEATURE_TABLE_SHIM:
            return False
        return False