Sample 1:

Item came out of South Africa so this particular shirt was likely used by SWAPO guerillas in Namibia.  The cut is identical to Cuban Elm Leaf and Grey Lizard camouflage shirts but in herringbone twill material. 

It was intended for export as seen by the English language “Made in Bulgaria” tag. 

The two pin holes above left chest pocket (from point of view of wearer) could be from a safety pin for a political campaign type button.

Usage Photo:

Items in the camouflage pattern were likely exported worldwide to Eastern-Bloc aligned groups.

Sandinistas (Nicaragua):

Sandinistas in Nicaragua, dated to 1980’s (from @camo_history on Instagram).

Angola:

Person with green beret on left of the Soviet advisor in the white shirt is wearing the Bulgarian pattern shirt.
Advisor to the head of the Special Operations Directorate (USO) of Angola, former “cascade” P. Suslov (center), together with a group of Angolan special forces after a successful operation against the sabotage group of the Buffalo [SADF 32] battalion. To the right of P. Suslov is the head of Angola’s USO Domingos “Stalin”, 1986. Copyright © Union of Angola Veterans 2005. (Советник начальника Управления специальных операций (УСО) Анголы, бывший “каскадовец” П. Суслов (в центре) вместе с группой ангольских спецназовцев после удачной операции против диверсионной группы батальона “Буффало”. Справа от П. Суслова – начальник УСО Анголы Домингуш “Сталин”, 1986 г Copyright © Союз ветеранов Анголы 2005) (Photo from Page 17, Photo 58 of Part 1 PDF at http://veteranangola.milportal.ru/ob-organizatsii/veterany-angoly-ot-proshlogo-k-nastoyashhemu-fotoalbom/; Caption from alternate photo of same event at https://www.veteranangola.ru/main/gal?id=426).