Both involve time travelling and have a interesting relationship with the king, when I was searching for dramas similar to BAYM I found splash splash love, it’s pity that it’s only two episodes
if you like saeguk dramas set around 10th century in Korean dynasty of Goryeo and stunning architecture, outfits, aesthetics, epic love stories and supernatural things like magic and time travel, moon lovers is for you (also hwarang set around 6th century AC)
