On chess.com, im pretty sure they all go through
what happens

Yes, players equal on tiebreak will both advance (or all advance, in the case of 3 players). The same thing happens when only one player is supposed to advance.

There isn't a second tie-breaking system. Β If more people advance than was originally expected, the number of groups in the next round can be adjusted to fit the new total number of players. Β Suppose you start with 8 groups in Round 1 and the rules say 1 person advances from each group. Β The TD's original plan is for Round 2 to have 8 people divided into 2 groups of 4 each. Β If there's a tie in Round 1 that results in 9 people advancing to Round 2 instead of 8, the TD could rearrange Round 2 to be 3 groups of 3 players each.
If the number of advanced players can't be divided into reasonable equal groups, there's nothing requiring the groups to have equal numbers of players. Β I'm in Round 2 of a tournament that advanced 8 players out of Round 1, but one of them must have dropped out or something, because now we have only 7 players in Round 2. Β For Round 2 we have 3 players in Group 1 and 4 players in Group 2.
hi,
what happens in a tournament if the score and tie break is equal for three players while 2 are going to the next stage??