Auto-default the requisition 'Primary Location' field

Summary:

Have any other customers found a way to default the requisition structure field 'Primary Location' based on the work location of the position?

Content (please ensure you mask any confidential information):

We currently auto complete the primary location with 'United Kingdom' for all of our Food Stores to make it easier for managers to raise. As we don't use the native career site, we send position work location to our 3rd party career site, so this has never been an issue for us. However we have switched job alerts on and as all of these requisitions don't have a specific location, candidates are recieving job alerts fo jobs in random places so we need to start populating the field with a Town location.