As the first mode is performed, first the opponent whose turn it is (or, if it’s not an opponent’s turn, the next opponent in turn order) chooses a creature they control, then each other opponent in turn order does the same, knowing the choices made before them. Then all the chosen creatures are sacrificed at the same time.

If Kaya’s Guile isn’t entwined, you must choose two different modes.

Each chosen mode is performed in the order specified. Abilities that trigger while one mode is being performed won’t be put onto the stack until Kaya’s Guile has finished resolving.

A creature sacrificed for the first mode of Kaya’s Guile will be exiled if it ends up in an opponent’s graveyard and the second mode was also chosen.