The calculated distance (air line) between Al ‘Ubaydīyah and Nablus is approximately 35 miles respectively 56 kilometers.
By car or train, the actual journey to Nablus is certainly longer, as only the direct route (as the crow flies) between Al ‘Ubaydīyah and Nablus has been calculated here.
Air line (approximately)
56 kilometers
30 nautical miles