Options do not appear using choice_filter after select_multiple question


I want to display all wards of the multiple selected districts using choice_filter, but this does not seem to work. I tried a lot of different things, but the most used formula in the choice_filter for this purpose seems to be of the type "selected(${name}, name)", but in my case this does not seem to work. I tried it both with KoBo Toolbox as with ODK Collect. Their is no problem on the choices tab, as it works perfectly with select_one followed by a choice_filter.

As a new user I cannot attach files so I'll try to show it clearly below:

select_multiple district trade_district Select the Districts where you usually do business
select_multiple ward trade_ward Select all the Wards where you have bought cassava or beans before selected(${trade_district}, trade_district)

Thank you for your support!