With equal points in a pool, the system first looks at the head-to-head result: who won the match between the teams involved?
If three teams are tied, a mini-league is made between those three teams. The team with the most points from these mutual matches wins.
Then goal difference (or set difference) is considered, and possibly goals scored. You can adjust this order yourself in Puntentelling > Regels bij gelijke stand (scoring > tiebreaker rules).
The system then creates a mini-league between those three teams: only their matches against each other count. The team with the most points from those matches wins.
Next comes goal difference (or set difference), and possibly goals scored. You can change that order yourself under Scoring > Tie-break rules.