Chech block nearby with tag

I’ve had a long-standing problem with tree generation, and I recently found a potential solution. However, I’m struggling to put the procedure together, so I’m asking for help with this.

What I’d like to achieve is that when a sapling is placed, the game checks the blocks surrounding it. If there’s a solid block within a specified area, it doesn’t generate the features. But if there are no solid blocks in that area, it does generate them.

I’ve tried putting together several versions, but none of them worked. I’ve been trying for weeks. Could someone put one together for me and show me what I should have done? :'(