This summary is not the rule. The rule text controls.
When a family law case has several different issues or claims mixed together, the judge has the power to split them up and handle them in separate trials instead of one big trial. This might happen with different claims someone has made, counterclaims, or claims involving a third party added to the case.
Judges usually make this choice for a few practical reasons. Splitting the trial can make things easier to manage, keep one issue from unfairly influencing another, or help the case move faster and cost less money. For example, if a case involves both a custody dispute and a separate financial claim, the judge might decide it makes more sense to deal with them one at a time rather than all at once.
This gives the court flexibility to handle complicated cases in a way that makes sense, rather than forcing everything into a single trial when that would be confusing or unfair to one side.