TOC for section B in section A in a document with 30 sections

Doug_Robbins_Word_MVP I inserted sections between everything. In fact, there are 2 sections per document so I can number the TOC pages separately. My huge problem is that the TOC is for the full document, not per section, let alone I want the TOC of Unit 1 in section 1 of Unit 1, and its headings to come from section 2 of Unit 1, after which I insert a new section  for TOC of Unit 2 referring to the 4th section,  contents of Unit 2. I spent days combining the docs, and when I printed, all the TOCs that I manually adjusted to just ccover their ssections had error codes and I had to update the fields to the full doc's TOC - exactly what I'd done the work around for. I don't see any way but separate documents for separate TOCs - and it's a pain in the butt, I've merged, updated, fixed and kludged everything, now have to extract it again. Is there an MS solutionn or better software for this?