Some questions about KO classification

[SDPA_Pet]

Hello, I have some questions about the KO classification.

I have a KO function abundance table. It will give me the basic level of KO funcitons ( the lowest level). Results like this:

#OTU ID Sample1

K01365 0
K01364 0
K01361 17
K01360 0
K01362 70832

KEGG database has higher levels of categories, which give me level 1, 2, 3.

For example I am interested in level 3, nitrogen metabolism category

I want to filter out all the KO functions related to nitrogen metablism

I want to create a table like this

#OTU ID Sample2
Nitrogen metabolism K0111 2
Nitrogen metabolism K0112 20
Nitrogen metabolism K0112 3000

This will help me to extract the functions that I am interested in. Anyone knows how to do this? -- extract all functions related to a category.

Also, I want to know the gene name of the KO funcitons.