Yes that is true. In restricting heading levels in the TOC using mc-heading-level statements in the CSS for each heading style, you also restrict those that can be displayed in the mini-TOC. A heading must have an mc-heading-level greater than 0 to be displayed in the mini-TOC, same as for the master-TOC.
It is possible to go the other way around and have the master TOC show more levels than the mini-TOC. So a mini-TOC can be a subset of the master TOC but not the other way around. Apologies, I thought I had worked out a way to do this in my own documentation but taking a closer look I ended up having to make my master TOC show the levels I needed in mini-TOCs.
Can you use another kind of proxy instead of the mini-TOC?
My intention was to show only h1 in the TOC and per chapter all the underlying paragraphs (by a mini TOC).
Because my TOC would be that long otherwise.
No, I think I cannot use some other proxy to achieve this.
Example of my intention:
TOC:
h1: Chapter one .............. on page x
h1: Chapter two .............. on page x
h1: Chapter three ............ on page x
etc.
mini TOC:
1 Chapter one
(first page inside Chapter one)
h2: Paragraph one ............. on page x
h2: Paragraph two ............. on page x
h3: Sub paragraph one ... on page x
h2: Paragraph three ........... on page x
etc.
2 Chapter two
(first page inside Chapter two)
h2: Paragraph one ............. on page x
h3: Sub paragraph one ... on page x
h2: Paragraph two ............. on page x
h2: Paragraph three ........... on page x
etc.
Is it possible to use a "LIst of" proxy that creates a list of H1 paragraphs and use that instead of the master TOC proxy? That way you can then add mc-heading-level statements to your H2 and H3 styles to get the appropriate depth for your mini-TOCs?