practical examples of "cross refernce" component for clarifying function of that

hi

for simulation of a skyscraper , i imported typical plan of each floor to GH , the building included 9 sectors (each sector is 6 floors and public spaces between them).

for creating a sector i used "move" component in order to make 6 floor of sector indicated in picture, but my problem is in next operation.

i used "move" component again for creating 9 sectors, but i dont know why lowest floor is moved only. it is according to instructions of primer book that i am reading. "cross reference" mode has been instructed , but i cant find that in component (the book has been written for older versions) , how can i find that?

The function of "cross reference" is vague for me , especially in this case, i need practical examples for clarifying function of that.

thank you