Exclude one metaball from interacting with another metaball only In the image below, Is there a way to make A and B not interacting with each other, but both interact with the U meta-balls?



I need to prevent A (specific metaball) from connecting to B even if there surfaces intersect, but both (A and B) should keep connected to the U.

Hard to explain.
There isn't much that can be done in this case. Metaballs do not have a lot of functionality in Blender. You could just insert a plane between them and set it to negative. It does deform them, so it is not ideal, but there are no other solutions as far as I am aware if you want to keep them as metaballs.