Came out of South Africa so was likely used by SWAPO guerillas in Namibia. Item was intended for export as seen by the “Made in Bulgaria” tag. The cut is identical to Cuban Elm Leaf and Grey Lizard camouflage shirts but in herringbone twill material. 2 pin holes above left chest pocket (from point of view of wearer) could be from a safety pin for a political campaign type button.
Also used by other Eastern Bloc aligned insurgents worldwide, such as the Sandinistas in Nicaragua:
From @camo_history on Instagram, dated to 1980’s.