Update cascading fields values based on other field selection

[Peter Newton]

Hi

I need to make 3 fields work togeder and I'm having hard times with cascading select update.For this, I'm using scriptrunner - behavior

Maybe someone did it already and can help me with a code

On create issue screen i have 3 fields. Field A, B and C

Field A is a simple single select

Field B and C are cascading select 

They are all defined and have values

I need to hide certain values from cascading select fields as follow:

When I select a value in Field A, the values from parent of Field B should be filtered and only some of them should be available for selection. The values from child of Field B should be updated according to parent selection.

Continuing, when I select a value in parent of Field B, the the parent of Field C should be filtered and only some values should be available for selection 

Can anyone help with this, please?

Thanks!