How to Fix assembly to the part of another assembly

Hi,

I'm trying to make MCD simulation from three assemblies imported from PARTdataManager (Cadenas), but I have a problem with fixing one assembly to a part of another assembly.

For example: First assembly has a slider which needs to move with Sequence Editor 1000mm in one direction. To that slider, I have attached second assembly with Assembly Constraints tool. Slider and second assembly are now in correct position relative to one another.

Now after I add an operation to the Sequence Editior which moves slider (from first assembly), second assembly doesn't move together with slider.

So my question is how to fix an assembly to a part (of an assembly) which is going to be moved by MCD simulation?

Attached is a picture of Assembly Navigator, and default position of those three assemblies.

Thanks and best regards,

Matko