It is hard to understand what you did without further explanation. Are your layers parented to the null? Are you moving the null or rotating it? Maybe you can post a screenshot?
In general, if you have several layers parented to a null and animate the null, they will always move in a cluster if you animate the parent.
If you need to animate them independently, this iExpression can also be helpful:
Attach to Circle 2D Expression | mamoworld