Here are a few suggestions for your next trip from Sid(SRB)

In 2 hours, you can reach Belgrade, Vinkovci.

In 3 hours, you can reach Slavonski Brod, Brčko.

In 4 hours, you can reach Osijek.

In 5 hours, you can reach Užice.

In 6 hours, you can reach Szeged, Pécs, Velika Gorica.

In 7 hours, you can reach Zagreb, Sesvete.

In 8 hours, you can reach Karlovac, Kecskemét.