You will need to do it using a Microflow as the data source as in the pages you have access to the current user token which looks like this '[%CurrentUser%]' which contains the current user Object ID only, in the Microflows you have access to both current user variable (Variables always starts with $) and token, using the CurrentUser variable will allow you to reach/use the FullName attribute.
Why not use a microflow as datasource that does the retrieve? Because you first need to retrieve the account before you could use the Fullname. And this way you could also influance how much data should be retrieved and do some sorting.
I would say that this is just a flaw in the domain model,
EnteredBy by the sound of it should be stored reference to the System.User.
[YourModule.YourEntity_EnteredByUser = '[%CurrentUser%]']
Or the Owner attribute should be used for that particular entity.
[System.owner = '[%CurrentUser%]']