Aligenment of Drawing to the center

I have found an issues which often eapaer when I do recive a drawing adn I have to rework them.
Problem: I receive a drawing with 10 or more elements.
It is necessity that the item is steady seperated. I can’t combine them to ONE drawing.
Now I like to align that drawing to the center of my Shapr3D constrution desk.
BUT I can’t select them in the window element, and it is nearely impossible to select them all.
Do I have an issue in my brain winding that I do not find the solution?
Regards Lorenz