Yes, if an observer were present in a galaxy with a high redshift, meaning it is located at a significant distance from us, they would indeed have a different observable universe compared to our own. The observable universe is defined as the portion of the universe from which light has had enough time to reach us since the Big Bang.
The concept of the observable universe arises due to the finite speed of light and the finite age of the universe. Since light travels at a finite speed, the light from very distant objects takes a significant amount of time to reach us. Therefore, when we observe galaxies with high redshifts, we are essentially looking back in time. The light from those galaxies has traveled for a long time to reach us, and we see them as they were when the universe was younger.
If we were to be present in one of those high-redshift galaxies, we would see our surroundings, including other galaxies, as they exist at that time. However, the portion of the universe that we can observe from there would be limited to the region within the observable universe from that location. Anything beyond that distance would be beyond our observational reach.
This implies that there are parts of the universe that are outside our current observable universe, regions from which light has not had enough time to reach us since the Big Bang. These regions are often referred to as the "unobservable" or "beyond the horizon" universe. As time progresses and light from those regions reaches us, our observable universe expands, allowing us to see objects that were previously beyond our reach.
It's important to note that the concept of the observable universe is based on our current understanding of the expansion of the universe and the speed of light. As our knowledge and observational capabilities improve, our understanding of the universe's boundaries may also evolve.