Often there is a need to pass current culture from UI to the MCCF back end.
This could be done by setting CommerceRequestContext class.
var requestContext = new CommerceRequestContext()
Channel = channel ?? Channel,
UserLocale = language,
UserUILocale = language,
RequestId = Guid.NewGuid().ToString()
Then on the backend layer (in processor or something else), we could get the passed culture as following
string culture = CommerceOperationContext.CurrentInstance.RequestContext.UserUILocale;