https://www.refworld.org/docid/3ae6b5174.html
Acquisition of citizenship of BiH
General principles
Article 5.
Citizenship of BiH is acquired in accordance with the provisions of this law:
1.by descent
...
Acquisition by descent
Article 6
Citizenship of BiH descent is acquired by a child born after the entry into force of the Constitution:
1.both of whose parents were citizens of BiH at the time of the child's birth, regardless of the place of his or her birth;
2.one of the whose parents was a citizen of BiH at the time of the child's birth, and the child was born on the BiH territory,
3.one of whose parents was a citizen of BiH at the time of the child's birth, and the child was born abroad if the child would otherwise be stateless;
4.who was born abroad and one of whose parents was a BiH citizen at the time of the child's birth, provided that by the time he or she attains the age of 23;
-he or she has been registered for the purpose of being entered in BiH citizens register with the competent BiH authority at home or abroad, or
-he or she had taken up permanent residence in the territory of BiH.
Насколько я понимаю, если говорить конкретно получение гражданства по одному из родителей, то нужно до 23 лет либо получить ПМЖ в БиГ, либо быть зарегистрированным своим БиГ родителем с целью получения гражданства в "компетентном органе в БиГ или за рубежом". Что это конкретно значит, надо в консульстве/посольстве спрашивать. Ну, или если "поезд ушел" и 23 года исполнилось, то искать другие пyти.