How to launch an action only on a combination of clicks on certain objects?

Question

Unity

Good afternoon! I don’t understand how to do it, like, for example, in all sorts of strategies, when you click on a car, it stands out, then you click on a building - it goes there. And if you click on an empty space, the choice will drop from it.

I assume that somehow manually in the code you need to paint all these combinations?

Here's what I came up with:

script <b>InteractiveObject</b> //родитель всем, на кого можно нажать и выделить

script Car : InteractiveObject //эти "дети" переопределяют метод, который вызывается по клику на
script House : InteractiveObject // интерактивный объект и дальше...?

further I did not understand how. How can I make sure that something specific is clicked next? I sit and think, to find and come up with something similar until it turns out.

I will be glad for any help! Thanks