This refers to a live television performance by the on BN TV , a popular Bosnian-Serbian broadcaster.
The performance aired on BN TV (based in Bijeljina, Republika Srpska), likely as part of a folk music program or a holiday special where Dejan Petrović is a frequent guest. Where to Watch You can typically find this content on: dejan_petrovic_big_band_opancici_sitan_vez_bn_tv
Search for the exact string "Dejan Petrovic Big Band Opancici Sitan vez BN TV" to find the official upload from BN TV or the band's official channel. This refers to a live television performance by