DLL の依存関係を調べる。bin フォルダーに作られる .deps.json の中から同じ情報取れそうかも。

AssemblyReferences.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection.Metadata;
using System.Reflection.PortableExecutable;

static class Program
{
    static void Main()
    {
        var format = @"[path to dll files]\{0}.dll";
        string getFullname(string name) => string.Format(format, name);

        void getReferences(string target, HashSet<string> assemblyNames)
        {
            using var pe = new PEReader(File.OpenRead(getFullname(target)));
            var m = pe.GetMetadataReader();

            foreach (var rh in m.AssemblyReferences)
            {
                var r = m.GetAssemblyReference(rh);
                var name = m.GetString(r.Name);

                if (assemblyNames.Contains(name)) continue;

                var fullname = getFullname(name);

                if (!File.Exists(fullname)) continue;

                assemblyNames.Add(name);

                getReferences(name, assemblyNames);
            }
        }

#if true

        var target = "[dll name]";

        var assemblyNames = new HashSet<string>();
        getReferences(target, assemblyNames);

        foreach (var name in assemblyNames)
        {
            Console.WriteLine(name);
        }
        Console.WriteLine(assemblyNames.Count);

#endif
#if tru

        const int Tab = 2;
        static void writeTab(int nest)
        {
            for (int i = 0; i < nest * Tab; i++)
            {
                Console.Write(' ');
            }
        }

        void writeHierarchy(string target, int nest = 0)
        {
            using var pe = new PEReader(File.OpenRead(getFullname(target)));
            var m = pe.GetMetadataReader();

            foreach (var rh in m.AssemblyReferences)
            {
                var r = m.GetAssemblyReference(rh);
                var name = m.GetString(r.Name);
                var fullname = getFullname(name);

                if (!File.Exists(fullname)) continue;

                writeTab(nest);
                Console.WriteLine(name);

                writeHierarchy(name, nest + 1);
            }
        }

        writeHierarchy(target);
#endif
#if tru
        Console.WriteLine("----------------------------");

        foreach (var rh in m.TypeReferences)
        {
            var r = m.GetTypeReference(rh);
            var arh = getAsmRef(r);
            Console.WriteLine($"{m.GetString(r.Name)} {m.GetString(m.GetAssemblyReference(arh).Name)}");
        }

        AssemblyReferenceHandle getAsmRef(TypeReference r)
        {
            var h = r.ResolutionScope;
            if (h.Kind == HandleKind.AssemblyReference)
            {
                return (AssemblyReferenceHandle)h;
            }

            if (h.Kind == HandleKind.TypeReference)
            {
                var t = m.GetTypeReference((TypeReferenceHandle)h);
                return getAsmRef(t);
            }

            throw new InvalidOperationException();
        }
#endif
    }
}