Sorry for the bad explanation, but I want to make a focus for my mod unavailable till the player does a Specific Focus, but I have no clue how to. Can Anyone Explain how.

To try and ensure sense is made in the explanation "Focus A" is the focus you want to have completed before "Focus B" is available.

If you edit "Focus B" and select "Focus A" when you go to the "Prerequisites" box, this will make it so that "Focus B" is unavailable until "Focus A" has been completed.

If you wanted to have a focus on the other side of the tree to be completed first, and you don't want a huge line connecting them, you can use the following inside the "Available" box for "Focus B".

has_completed_focus = TAG_focus_a

(where TAG is the tag of the nation the focus tree is for, and "focus_a" is the name of the focus, lowercase, spaces replaced with _ and special characters removed)

And if you want a player to only take "Focus A" or "Focus B" (similar to Rhineland or Oppose Hitler in Germany's tree), then you use the mutually exclusive box.  

Alright Thank you