Multivalue listbox filter (1 Viewer)

I have a form called Clients that contains two multivalue listbox I can chose from the city list more than one city I need to show the districts on the other city that matches with the selected cities.

I have never seen cascading comboboxes attempted with multi-value fields.

Why is CityID in Areas a multi-value field? So a city has multiple areas?

Appears to be a circular relationship with the 3 tables.

Saving City into Clients doesn't make sense because there are multiple records in Areas for same city. Save the area and then city can be found via query through the area.

Hi June7, thank you for your quick response, actually it's a sample for a bigger project, I just submitted an example, but in the real world I have clients that has offices in more than districts in many cities.

This structure is going to make your database almost unusable in the real world.
1. Using table level lookups is a bad idea. See http://access.mvps.org/Access/lookupfields.htm
2. Multivalue fields make it very difficult to query and trying to use them to filter other fields would be a nightmare in my opinion. See http://www.mendipdatasystems.co.uk/multivalued-fields/4594468763
3. Relationships are based on the MVFs and in a loop. I'm fairly sure you will end up with read only queries.

Recommend you review your data structure to fix the above issues