Integrated field unit (IFU) spectroscopy provides a unique window to explore gas-phase metallicity in the interstellar medium (ISM) of galaxies in the local Universe. Two-point correlations are one of the next-generation methodologies proposed to extract new information on ISM diffusion from metal fields inside galaxies. I will present two-point correlation analyses using CALIFA and MUSE that show this approach is robust across local different datasets and can be a powerful tool to investigate the properties of the ISM of nearby galaxies when combined with an analytic model. The derived characteristic ISM diffusion length scales indicate that metallicity correlations in galaxies are influenced by the competition between turbulent diffusion and galactic outflows. Two-point correlation methods are also applied to the high-resolution Auriga simulations obtaining consistent results. The simulations reveal the interplay between internal and external processes on setting the instantaneous mixing scale and how it evolves with time. This new work provides new opportunities for next-generation facilities (e.g., VLT/ERIS, GMT/GMTIFS) to push this technique beyond local Universe where the ISM is expected to be more turbulent and galaxies are expected to host ubiquitous outflows.