Unable to create separate source



Have latest V of Kodi and am using Amber (not my ideal choice) – but it has the ability to add to the home menu, which my preferred, confluence, can’t

Video data is in 3 separate NAS boxes as follows
1) Film
2) TV-Shows
3) Documentaries
each of the 3 have a folder structure of #, A to Z – so 27 sub folders per Box – it’s neat and exactly as i need!

the above is NON-negotiable vis a vis change

I have created 2 sources (possibly may have done this in confluence before i switched to Amber) for movies & TV
i now need to
1) create a 3rd source to the documentary NAS
2) add that source to a ‘Documentary’ menu item on the HOME menu
when i look at settings i can see the two original sources but can neither edit them or create a new one

Need a ‘KISS’ solution – not some overblown, ’round the houses’ dsicusion.