Hi James,
No it should not, and normally you can leave this value empty. The dashboard will always show all data related with the current Xerte installation. The field is meant to be able to cahnge the URL of a Xerte installation to a different one but still be able to retrieve data created with the previous URL.
The fields in the properties of a single have a similar function, but on an individual project level. So, when you have a new LO, but also want to include the data of a different LO you can insert the path to that previous LO. So, also these fields are normally empty.
Cheers,
Tom