Paragraph numbering doesn't show up in TOC

I am working on a book with multiple chapters. Within each chapter, I have heading styles that use auto numbering (Heading 1 shows 1.1, 1.2, etc.; Heading 2 is 1.1.1, 1.1.2, etc.; Heading 3 is 1.1.1.1, 1.1.1.2, etc). These numbers show up fine in the chapters, but I can't seem to get them to show up in the generated TOC. I have tried adding <$chapnum>.<$sectionnum>.<$subsectionnum> to the TOC reference page, but that only seems to show the TOC chapter number, rather that the chapter the heading is actually in. I tried auto numbering in the TOC, but that didn't work either. Is there any way to show numbering from chapters in the TOC?

This is how it looks now:

Lab 3: Adding Redundancy to a Component

  Purpose ...........................................7 - 1

  Functional Goals.............................. 7 - 1

  Setup ..............................................7 - 1

  Code Files for this Lab...................... 7 - 2

This is how I want it to look:

Lab 3: Adding Redundancy to a Component

  7.1 Purpose ...........................................7 - 1

  7.2 Functional Goals.............................. 7 - 1

  7.3 Setup ..............................................7 - 1

  7.4 Code Files for this Lab...................... 7 - 2

If anyone can help me, I would really appreciate it!!!

Thank you!