Benching where you ate
In a meal of bread, one must bentch in the place of the meal, in the same place where they ate. If the person leaves the place where they ate, and it is before the Shiur called Shiur Ikkul, the time it takes for food to be digested, they may - and must - still bentch. One is required to go back to the place where they ate and bentch over there. According to some opinions, if one left the original Mokom Seuda deliberately and does not go back, they may not have fulfilled their Chiyuv of bentching if they bentch in the second place. However, according to Halacha, Sofeik Brochos LeHokel, and if they bentched in the second place, it is acceptable. Another solution would be to eat a tiny bit of bread in the second place and then one could bentch over there, although lechatchila, one is not supposed to leave the place where they ate before bentching.