Help with custom height for one piece after cutting one piece into 3

MakerWorld
1

17384548049248226154352881656814
173845480492482261543528816568141920×1080 190 KB

I split a large tower into 3, however the top piece I would like to scale the height down (Y) but when I try it select all 3 plates. As shown
17384549971805638579139167486121
173845499718056385791391674861211920×1080 158 KB

Is there a work round were I can I can just select the one piece on the one plate to custom set it height?

Many thanks

2

You probably selected cut into parts

3

I did to split into 3. Should I have done it a different way? Also thank you for the quick response

4

Split them into multiple objects instead, i am assuming you selected the cut to parts box. You can also select all of them and right click to split.