Filtering using list intersection and merge

I have two lists A and B
A contains the data that you want to display in RG
B is a list created arbitrarily by the user and may contain items from A.
Goal: Display all the list of A in RG, but if there is anything in B, it will be displayed on top with priority.

I thought this could be done with listB merged listA, but listB may contain items that are not included in A, so it cannot be used.
In my opinion, it can be done by merging A with a list that intersects A and B, but it does not work with the expression “listA intersect listB merged listA”
(Nothing is displayed)

How should I handle this?
Also, is there any other smart way?

You could do this as data source - list A intersect with list B merged with list A minus list list B

Sorry, it’s resolved
It seems that the intersecting ceremony was reversed… Sorry.