gistfile1.cs

var t = typeof(INavigateHere<>).GetTypeInfo();

var test = from type in assembly.DefinedTypes
    where t.IsAssignableFrom(type)
    select type;

gistfile2.cs

var test = from type in assembly.DefinedTypes
    from interfaceType in type.ImplementedInterfaces
    let interfaceInfo = interfaceType.GetTypeInfo()
    where interfaceType == targetInterface || interfaceInfo.IsGenericType && interfaceInfo.GetGenericTypeDefinition() == targetInterface
    select type;