If you set the top layer including transparency, you can not select the elements below it.
Even with any design tool, it is necessary to make it impossible to select it when locked.
I have many such situations, but I will give up if there is no demand
However, selecting a layer is not intuitive, it is troublesome, and it needs to be selectable visually and quickly.
It is impossible to quickly select the object of interest from among many layers.
In XD, it is impossible to feel what is possible with general design tools, so I feel stress.
Scott Barron commented
You can try using the layers panel and select the desired layer from there