Hello @MichelDiz,
I’m also in the need of such a mechanism.
I thought I would already work as the Query Variables doc says Query variables can be used in other query blocks or in a child node of the defining block.
But in the child node, the variable exists but is empty.
If I understand well, current variables are global and here we need variables with a scope local to the block and passed to its children.
Using 2 blocks only works if we manipulate one element, but when dealing with multiple elements, the variable merges all UIDs and the result is wrong.