I'm not sure I understand what you are asking. Are you having trouble generating the the data for a page list/page group named .Country()? I assume you are iterating through a list of something else and evaluating .CKInDate() for if present and not null. (is this scalar or a list/group?) Assuming it's present and not null, you get .Travel.Country (off the same object you just iterated through?) and map it to the next .Country() value, building the array that will ultimately be displayed in a repeating layout? I'm not sure why you are using an expression, verse a data transform or activity. Can you maybe add some screen shots or something for a bit of context, since I'm not entirely confident that my assumptions are correct?