How do I place a block only in another specific block?

Here I have made it for you 
This will check when you try to place it if there is Dirt or Coarse Dirt under if no than it will instantly break this plant also 
when you will try to place it in Survival it will spawn you its sapling or what ever you want just replace the popy from my example to something that you want or if you don't want it to spawn item when you break it on survival than remove that second If method :)
also place make this run on "Block Placed By Player" Event trigger to make it work and check Wiki for information's about Procedures :)

Wes i just wanted to thank you for sharing that code, i was having a hard time finding a way to specify block placement then i looked at this. Thanks a lot.

is there an update for this for 2023? sides of blocks like my Tree Tapper?

Hey TheRTGGaming, funny enough im making the same thing for my mod, and i figured out how to make it placeable on sides, you can copy the image ill put below, Basically i made an item for the block instead of directly placing it and set this code to the ITEM FORM of it, Note that it uses orange "=" blocks