How to use nested namespace to avoid ambiguity?

I have the following operators defined in the corresponding namespaces:

namespace literals
{

constexpr ID operator"" _ID(const unsigned long long dyngateID)
{
    // ...
    // return a constructed id
}

namespace multiplied
{

constexpr ID operator"" _ID(const unsigned long long dyngateID)
{
    // ...
    // return an id constructed in a specific way
}

} // namespace multiplied
} // namespace literals

In a .cpp file I would like to use both functions, hence I've declared using namespace literals and when I am declaring using namespace multiplied in a concrete function I am getting ambiguous call to overloaded function compile error. How can I differentiate these functions?

Test.cpp

using namespace literals;

void f()
{
    // here I am using literals' _ID which is fine
    const Type id{1_ID};
}
void g()
{
    // here I want to use multiplied's _ID, but obviously I am failing to do so
    using namespace multiplied;
    const Type id{1_ID};
}