Hi DM1 and Toltec,
Sorry for not replying sooner, I didn't get any notification on my mail that I was replied, so I thought nobody did, my apologies.
Unfortunately I use Affinity Photo, not so much Designer. And it doesn't seem to have this option there, so unfortunately I can't use it.
It's such a shame something as basic as being able to select layers underneath is simply not possible! I will always select the layer on top (like Autoselection in PS), forcing you to open the layer window everytime to find the layer underneath, it's really makes my flow really slow, so I decided to move to Artstudio where this option is simply there.
Thanks so much for your reply, really appreciated,
Manuel