This post: https://powerusers.microsoft.com/t5/forums/replypage/board-id/PowerAppsForum1/message-id/40826
really helpful, however, the values are for the current user only. For the app I'm building, the user has the ability to submit the form on behalf of someone else, so they can overwrite the 'Submitted By' and 'Line Leader' field.
I can't seem to work out how to extract the given name and surname for the particular user that is selected in the combo field. I tried the datacardvalue name but couldn't get it working. For the associated flow, it seems I can only select the Display name (surname, firstname) rather then given name surname. Unfortunately the users are not satisfied with DisplayName.
Any ideas, much appreciated.