I was also curious to try it sort. Unfortunately I could not find a way in the new UX to actually sort it in the drop down selector.
But as a workaround, you could publish a grid dimensioned by this hierarchy and will apply sorting, it could be used as a navigational grid - end user need just to click to a right product and this selection will be synchronised.
In the dashboards I could not order it with all parent hierarchies, but it seems that you could sort a flat product list without hierarchy.
Here are my steps:
1) I have a sorting line item which is calculated via RANK function. I could adjust position by changing values in COUNT lineitem.
2) I will do "reselect levels to show" to display only products L2 (P3 in your case)
3) I changed Count value for product "Nougatacious" to change its position from 6th to1st.
4) I pivoted dimension and saw that my sorting was saved.
5) I played with other product values to re-order them dynamically and they were changing position in a drop-down page selector list.
I am afraid that I tried a similar approach but it didn't worked out. The sort order will preserve in the module but when you publish this as a page selector on the dashboard, the sort order doesn't preserves.
I've tried to publish this on a dashboard - it is still working, but I have just a dimension of a products.
It may happen that this would not work the same way with more dimensions in a module.
But from a UX design perspective I would still rather go ahead with "Navigation Grid" that allowed you to rank products more flexibly and simple in maintaining as well applicable both for UX/Dashboards.
You are correct the sort order will be preserved when it is published as a page selector in a module, but when we publish the list as a page selector for the dashboard, the sort order is not preserved. That's what the ask whether we can sort it or not
As others have confirmed it is not possible to dynamically change the order of items in a list. My suggestion is to change the list order manually or reimport the list already sorted. When new items are add make sure to add them into the list at the required oder.
I tried using the order list action but it is not working for me. I have a composite list to sort having the hierarchy P1->P2->P3.
I am sorting the P3 list(a numbered list) using the sort criteria as the the display name for this list. So whenever I am running this order list action, nothing is happening. The order remains the same.
Can you please help me with this.
Also will this sort the list published as Page Selector too on Dashboard ?