Recent surveys and instruments provide an extensive amount of data for our Galaxy that are key to revealing its assembly history. In this talk, I will present the results of my PhD thesis, first, a dynamical model of the Milky Way disk using the spherically-aligned Jeans Anisotropic Method and combined Gaia EDR3 and APOGEE data throughout Galactocentric radii between 5.0<\; R<\;19.5 kpc. Further, I focus on omega Centauri, the most massive globular cluster in the Milky Way, which has long been suspected to be the stripped nucleus of a dwarf galaxy. I present a MUSE spectroscopic dataset with more than 300,000 extracted stellar spectra. Using this dataset, I investigate the underlying metallicity distributions as well as the spatial variations of the populations within omega Cen for the red giant branch stars. Our unprecedented dataset combining spectroscopy with a new astro-photometric catalog is enabling innovative studies that will transform our understanding of omega Cen.