Nested Entities Reference - Confused

I have been working my way through my first stand alone application.  It is broadly based on the Contosso University tutorial and I am working in Asp.Net Core.

So far, I have been having pretty good results and think I have a good grasp on the basics...it took a while...but I got there.

However I am now moving a layer out from the code I knew would mimic the tutorial to a large extent.  I have a bit of confusion on this aspect.

Within the SitesController I have the following:

 public async Task<IActionResult> Details(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var site = await _context.Sites
                .Include(w=>w.SiteType)
                    .ThenInclude(w=>w.HealthGroup)
                .Include(w => w.WaterBodys)
                    .ThenInclude(w => w.Equipment)
                    .AsNoTracking()
                .SingleOrDefaultAsync(m => m.SiteID == id);
            if (site == null)
            {
                return NotFound();
            }

            return View(site);
        }

This works fine.  As can be seen I have a table HealthGroup.  Health Group includes Group id.

In relational model I have several other tables that use GroupID to return more information.  For example First Aid Kit requirement.

My data model in rough is:

Health Group - data specific to the group

HealthGrouptoAid - linking table.  Different groups have different first aid kit requirements for ease say group 1 has 1,2,3; group 2 might have 3,5,8 etc

HealthFirstAid - contains the requirements e.g. stretcher, pillow and blankets etc

I feel like I need to write something like:

            var site = await _context.Sites
                .Include(w=>w.SiteType)
                    .ThenInclude(w=>w.HealthGroup)
                          .(Then)Include(w=>w.HealthGroupToKit) //assuming this picks up the GroupID from Health Group
                              .(Then)Include(w=>w.HealthFirstAidKit) //assuming this picks up from HealthGroupToKit
                .Include(w => w.WaterBodys)
                    .ThenInclude(w => w.Equipment)
                    .AsNoTracking()
                .SingleOrDefaultAsync(m => m.SiteID == id);

However this doesn't work and intellisense is telling me it is wrong.  I am not sure what to Google to find an example of how to do this.  I am hoping someone here may be able to assist me in improving my understanding and enabling me to move past this roadblock.