Herein, we describe a condition‐based switchable Rh(III)‐catalyzed C‐H alkylation and alkenylation of 1,2,3‐benzotriazinones with maleimides, where triazinone serves as a directing group rather than its traditional role denitrogenative precursor. This strategy enables the selective synthesis of diverse 3‐arylated succinimides and 3‐arylated maleimides in up to 99% yield with broad substrate scope (48 examples). Furthermore, for the first time, a tandem C‐H alkylation and denitrogenative coupling of 1,2,3‐benzotriazinones has been realized by slightly modifying the reaction conditions. Additionally, gram‐scale reactions and product derivatizations were conducted to demonstrate the synthetic utility.