sub-sub-niche

i stumbled upon a site where i searched for new ideas for a site I'm planning to create, so this site may help someone who is searching for a Sub-Niche whiting a niche! https://www.dmoz-odp.org/ Click on the Broad niche you're interested in, and then niche down to the sub-niche you're...

I am working on a Sub-Sub-Niche and want to use same as my keyword. The Niche is low competitive. But the Traffic may be huge if I rank on Google. I have domain with the same keyword to... What are the ways for ranking on a Sub-Sub-Niche?