I’ve been working with UE4 for about a week now. My third project is an AI miner. The goal is to have a NPC find nodes in a level and attack them like a normal character would to gain resources. The problem I am having is the NPC finding the nodes. I’ve learned how to let an AI find players but allowing them to find non-player objects like trees or in this case rocks alludes me. Can someone point me into a direction to accomplish this goal?
what I would do is using a multi sphere trace by object to detect surrounding objects and then use an actor as dummy placed on the foliage where you want your AI to go get resources…Move the AI to the dummy actor where you get the reference by the sphere trace, if you have a lot of foliage and you want your AI move to closest foliage then take your array of detected actor, check the distance between the AI and the dummy actor and move to the actor location and play a custom anim per example… Let me know if you need more info! 
The short “point-me-in-the-right-direction” answer is EQS. Obviously the whole thing depend on how good your C++ is.