this one from Eastern Europe the Bugarija,('a Croatian instrument used in tamburica ensembles' )
the treble strings are a unison pair.
I was told, they are traditionally tuned as many do the Appalachian dulcimer , to an open chord,
or as the player in the WA group 'Balkan Cabaret', played it .. as a tenor guitar
DGBee.. being a guitar player .. the instrument is guitar shaped , after all.