Restricting enum options in inspector when using a propertydrawer.

I'm not sure if this is possible as I am quite new to PropertyDrawers in C#.

What I want to do is make it so you choose a item type from a list, such as pistol, shotgun, rifle, first aid.

Upon doing so I want a second box to appear for a sub-type, such as ammo, magazine, bandage, pills etc etc.

however I want only want certain values to show up in the sub-type depending on the main-type.

So when you choose "First aid" I do not want options such as "ammo" and "magazine" to show up in the selection. Where as "pistol" will have "ammo" and "magazine" but "shotgun" will only have "ammo".

Any help will be appreciated.