Subsidiarity is a principle of social organization that holds that social and political issues should be dealt with at the most immediate or local level that is consistent with their resolution. Wikipedia

Principle of social organization that holds that social and political issues should be dealt with at the most immediate level Wikidata

The principle that initiative (whether in government, business or religion) ought to reside at the lowest feasible level (i.e. at the local or regional level, instead of the national or supranational level, unless the latter presents clear advantages). Wiktionary

Principle. Wiktionary (translation)