Was just exploring the advanced condition builder added to the Power Automate (Flow) beginning of the last year.
The new conditional builder makes it very easy to write complex conditional logic compared to using expressions.
We can easily add row (conditions) and group them
The row (condition) can be grouped by either And or Or.
To simplify the view, the group can be collapsed.
The group can be deleted, moved up or down along with ungrouping.
For complex expression, we use the regular Dynamic Content expression builder to enter in the left side of the row as shown below.
Total 10 conditions can be added after which the option of adding more option gets disabled.
We can add a group as the 10th row and again add conditions in that row.
Similarly, 10 group as row can be added
Similarly, we can have 5 nested groups
The below post by Benitez Here explains it best, and includes comparison with the workflow designer.
Hope it helps..