In Drools Workbench, I defined a dependent enumeration like:

'fact.f1' : ['a','b']
'fact.f2[f1=a]' : ['a1', 'a2']
'fact.f2[f1=b]' : ['b1', 'b2']

The enumeration is detected properly and the drop-down box is displayed for Guided Rules and Test Scenario GIVEN section.

The dependent filed is not detected properly for the Test Scenario EXPECT section and instead of the drop-down box a simple text box is displayed.

If I populate the text box with a correct value from the enumeration, the scenario reports success, so the rule and the scenario is correct.