What's the adjective for metroplexes? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs metropolitanise and metropolitanize which may be used as adjectives within certain contexts.
metropolitan
(Christianity) Pertaining to the see or province of a metropolitan. [from 15th c.]
“In addition, there are six extraprovincial churches, five of which are under the metropolitical authority of the Archbishop of Canterbury.”
“Until 1920 the Welsh church was part of the Church of England and under the metropolitical jurisdiction of the Archbishop of Canterbury.”
“In 1974, the Archbishop of Canterbury gave over his metropolitical authority for the dioceses of the Southern Cone and in 1981, the new province was formed.”