multidropdown items selection during "Update" related action

Hi hari,
your issue is, that you choiceValues are elements of "languageNumber" and your value is a "whole" CDT:
To make this work some inputs:

local!languages:....,
local!selectedLanguages: ri!employeeLanguage,
local!selectedLanguageNumbers: index(selectedLanguages,"languageNumber",null),
....

a!multidropdownfield(
....
    choiceValue: tointeger(index(local!languages,"languageNumber",null)),
    value: tointeger(local!selectedLanguageNumbers),
    saveInto:{
       local!selectedLanguageNumbers,
       a!save(
        target: local!selectedLanguages,
        value: index(
            local!languages,
            wherecontains(
                tointeger(local!selectedLanguageNumbers),
                tointeger(index(local!languages, "languageNumber,{}))
            ),
            null
        )
       )
    }
)

is languageNumber your primaryKey? if not , try to use the primary key instead