Die-to-die (D2D) placement is a more challenging stage in achieving higher performance with complex constraints, critically impacting timing, power, yield, cost, etc. Existing placers often rely on indirect objectives (e.g., considering cut sizes in tier assignment), which can lead to a loss of the overall solution space utilization and may even deviate from the actual objective. To address this issue, this paper leverages the natural dominance relationship between decision variables to transform the original problem into a bilevel programming problem equivalently. Additionally, an alternating optimization framework is introduced to enhance the exploration of the overall solution space. On the one hand, we propose two tier optimization operators for simultaneous optimization of wirelength and #terminal in global and detailed perspectives; On the other hand, we present a near-optimal terminal legalization algorithm following an efficient multi-tier co-placement. Compared with the top three winners of the ICCAD'22 contest, our placer achieves 4.33%, 4.42%, and 5.88% smaller wire-length, 79.61 %, 16.74%, and 15.76% fewer #terminal and competitive runtime. Moreover, our placer always uses the fewest #terminal and achieves amazing wirelength reduction when the terminal size changes.