If you look at the classic "pulp" magazines from the 20s, 30s, etc. you will find they sometimes had more than one table of contents. Usually on the same page, but they would often have one table of contents for the short stories within and a second table of contents for things like poems and comic strips within.
I can give a link to one on archive.org if necessary.
I am attempting to do the same (I'm creating a pulp-style magazine) and in LaTeX it is easy - just use the tocloft package and you can have as many table of contents as your heart desires. But trying to do it an ePub - works in the readers I tried, but results in a validation error.
What I am using is using a separate html5 nav element for each one, but assigning each one with the attribute epub:type="toc"
Each nav element then has an h1 child with the name of the ToC and an ol child with the links to the content.
But Epubcheck 4.0.2 at
https://www.epubconversion.com/epub-validator/ gives the following error:
``RSC-005 (ERROR) Message: Error while parsing file 'Exactly one 'toc' nav element must be present'.''
Given that there is historical precedence for multiple ToC in pulp magazines (and also in academic references where List of Figures and List of Tables are common) I find it hard to believe that ePub doesn't have a way to do this.
What is the proper way?