Enumeration in microflow

Hi, I have an entity ‘World’ and have two Enum attributes ‘Country’ and Cities’ . When user sign up, he should choose a specific Country he belongs to. Upon log in he should get the Country which he selected during sign up (non-editable field)  and based on Country the form should show Cities in dropdown which comes under only that Country. I have created microflow and I can get the Country for that user but not able to fetch list of cities into City Enumeration.  
1 answers

Your domain model needs to look something like as shown below. 

User will be able to select the list of countries coming from reference_selector based on country names and city name should be based on the selected country, stored in the user attribute and the list of names should come through the association.

How will you this this association in Enumeration? There is no filtering in Enumerations.