Prevent transparent object from being visible through itself?

I made this tree here and I am pretty happy with it so far. I have a problem though. As you can see the picture, I have some tiny bush-like things attached to the tree. Because the tree is transparent you can see small thing behind the bigger leave-bundle. When the Smaller one lies in the shadow of the big one, it really sticks out, because of how dark it is there. Is there a way to prevent an object being visible through itself?

Note that those dark things visible through the tree are not the backfaces.
I have heard of cut-out shaders, but I all leaves turn completely transparent and cast no shadows anymore.
Im using HDRP in the newest Unity 2020 release.

Thank you all very much for your time and help.