battalion tactical group

Short definition from Wiktionary

Noun

1. 1
   A military unit of the armed forces which incorporates multiple branches of the military within a single command structure (also known as combined arms).
2. 2
   A combined arms military unit that is used for specific tasks and to achieve a discreet mission. Originated during the Soviet invasion of Afghanistan; also used significantly during the 2014 and 2022 Russian invasions of Ukraine.