How Do I Add Subsection in Taxonomy

Quick question, I wanted to add a subsection to one the header field (located in taxonomy) and cannot figure out the correct way to go about it.

I have examined the nodes within each taxonomy field and can seem to find where to insert a subsection. Currently we have a tab labeled “about us” in the header of the website and I would like to add a couple of subsections (meet the team, our founder, mission statement ext…) underneath the main category.

I was hoping someone in the community could point me in the right direction, any assistance would be super helpful.