Three Level custom fields

here we have to maintain “Category → Sub-Category → Item” flow when we are picking them from custom fields , how to manage this all ? , we are able to manage till sub category level , but not for item level , we want dropdown at the item level which is based on description of resolved issue , please help for the same

From what I understand, the requirement is as follows:

Category is the topmost level field
SubCategory is dependent on value selected in Category
Item is dependent on value selected in SubCategory

I have been trying the same but running into an issue where in the Item field does not show any dropdown values based on the SubCategory.

@GreenJimll @knation


Who would tell me how to solve this problem?))