In Photoshop, “cropping” is inclusive of any & all layers. But to achieve the same thing for just one layer, it’s just a matter of:
1) Select the area you want to keep (doesn’t necessarily need to be rectangular, as with normal cropping).
2) Use Select—> Inverse to reverse the selection to its opposite.
3) Press Delete.
BTW, these steps could be recorded in an Action, then assigned to a button, readily available for one-click layer cropping.