How to add filter for topo features variable?

Hi everyone!
I'm trying to create a filter in Validator updateParameters() for my topo features variable.
I figured out how to set value using list of lists:
self.params[0].value = [[1, 2, 3], [4, 5, 6]]
But something like
self.params[0].filter.list = [[[1,2], [], []], [[], [], []]]
doesn't work.
Please help.
Nick