country of residence; jurisdiction of residence
Formal term used in legal, tax, and administrative contexts to refer to the country where a person lives.
I will explain the tax obligations in your country of residence.
Please follow the procedures according to the laws of your country of residence.
居住地 means 'place of residence' (could be a city or region), while 居住地国 specifically refers to the country of residence.
国籍 means 'nationality', which is distinct from 居住地国 (country of residence). A person can reside in a country without holding its nationality.
Compound of 居住 (residence) + 地 (place) + 国 (country). The exact historical derivation is uncertain, but the components transparently combine to mean 'country of residence'.