sharepoint online – Auto populate 2 People Picker fields based on another People Picker Field

You can retrieve user Login and User Display name and then you can use function(below) to resolve people picker.

var currentUserLMEntry = createUserEntity(currentUserData.managerLogin, currentUserData.managerDisplayName);
function createUserEntity(userLoginName, userDisplayName)
{
return {
  Description: userLoginName,
  DisplayText: userDisplayName,
  EntityGroupName: "",
  EntityType: "",
  HierarchyIdentifier: null,
  IsResolved: true,
  Key: userLoginName,
  MultipleMatches: (),
  ProviderDisplayName: "",
  ProviderName: ""
};
}