According to current scientific understanding, the visible universe, also known as the observable universe, is a portion of the entire universe that we can observe from Earth. The observable universe is limited by the distance that light has had time to travel since the Big Bang, which is estimated to be about 13.8 billion years. This distance is approximately 93 billion light-years in diameter.
As for the percentage of the total expanding universe that lies beyond the observable universe, it is challenging to provide a precise figure. The expansion of the universe and the structure beyond the observable universe are still areas of active research and investigation in cosmology.
Based on current theories, it is believed that the universe may be significantly larger than the observable universe. Inflationary cosmology, for instance, suggests that the universe may have undergone a period of rapid expansion shortly after the Big Bang, resulting in a much larger cosmos. However, the exact size and extent of the universe beyond the observable portion remain uncertain.
To summarize, while we can't determine an exact percentage, it is likely that the portion of the expanding universe beyond what is currently visible to us is considerably larger, potentially even infinite in scale.