Labor Union Act Article 8

Labor unions may organize a confederated labor union. The name, level, district and type of the confederated labor union shall be prescribed in its union charter.A confederated labor union shall have full-time personnel to process its union affairs.In case a confederated labor union is organized on a nation basis, the number of labor unions proposing to organize it shall reach over one-third of the total amount of labor unions of the same type, and the labor unions proposing shall spread in no less than one half of municipal cities, counties (cities) of the whole nation.
中文原文 工會法第8條
工會得依需要籌組聯合組織;其名稱、層級、區域及屬性,應於聯合組織章程中定之。
工會聯合組織應置專任會務人員辦理會務。
以全國為組織區域籌組之工會聯合組織,其發起籌組之工會數應達發起工會種類數額三分之一以上,且所含行政區域應達全國直轄市、縣(市)總數二分之一以上。

English translation for reference only; the Chinese text prevails. Not legal advice.