IncludeFilter multiple levels not working - entity-framework-6

Question

Having problems with this IncludeFilter and including multiple levels. I'm using Entity Framework 6 Plus.
This is the example they provide https://entityframework-plus.net/query-include-filter under the Load multiple levels heading.
This works, but it returns more warranty records than I want.
db.Application.Where(x => x.ApplicationId == applicationId)
.Include(x => x.Lienholder)
.Include(x => x.Warranty.Select(y => y.Coverage.CoverageGroup))
.Include(x => x.Vehicle)
.Include(x => x.Vendor)
.First();
This works but .Coverage is null, but it's the closest one to the example.
db.Application.Where(x => x.ApplicationId == applicationId)
.Include(x => x.Lienholder)
.IncludeFilter(x => x.Warranty.Where(z => true).Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
)
.IncludeFilter(x => x.Warranty.Where(z => true).Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
).Select(y => y.Coverage.CoverageGroup))
.Include(x => x.Vehicle)
.Include(x => x.Vendor)
.First();
This doesn't work at all because apparently with IncludeFilter you have to include a where clause
db.Application.Where(x => x.ApplicationId == applicationId)
.Include(x => x.Lienholder)
.IncludeFilter(x => x.Warranty.Where(z => true).Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
).Select(y => y.Coverage.CoverageGroup))
.Include(x => x.Vehicle)
.Include(x => x.Vendor)
.First();
This one works but it doesn't eager load Coverage
db.Application.Where(x => x.ApplicationId == applicationId)
.Include(x => x.Lienholder)
.IncludeFilter(x => x.Warranty.Where(z => true).Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
)
.Include(x => x.Vehicle)
.Include(x => x.Vendor)
.First();

Answer 1

You cannot mix Include with IncludeFilter or IncludeOptimized.
You need to include every path once in his own IncludeFilter
In your closest example, you missed to include "Y.Coverage"
Those are currently limitation of the library.
Here is what you are looking for:
db.Application.Where(x => x.ApplicationId == applicationId)
.IncludeFilter(x => x.Lienholder)
.IncludeFilter(x => x.Warranty.Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
))
.IncludeFilter(x => x.Warranty.Where(z => true).Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
).Select(y => y.Coverage))
.IncludeFilter(x => x.Warranty.Where(z => true).Where(z =>
z.WarrantyStatusId == 2 ||
z.WarrantyStatusId == 3 ||
z.WarrantyStatusId == 8 ||
z.WarrantyStatusId == 10
).Select(y => y.Coverage.CoverageGroup)))
.IncludeFilter(x => x.Vehicle)
.IncludeFilter(x => x.Vendor)
.First();
This doesn't work at all because apparently with IncludeFilter you have to include a where clause
No, you don't have.