Gaia DR3 PMs referred to the systemic values of Liller 1 (from Vasiliev & Baumgardt 2021), for the stars with a magnitude comparable to that of the spectroscopic targets (G < 19) and located within 2 arcmin of the center of the system (gray dots), where the 22 spec-troscopic targets (color-filled circles and squares) are also located. The red-filled circles and blue-filled squares are likely member stars of Liller 1, belonging to the metal-poor and metal-rich subpopulations, respectively (see Sect. 3.2). The typical error bars for the spectroscopic targets are reported in the bottom-right corner. The large dashed circle has a radius equal to three times the PM dispersion of Liller 1 (see text). The spectroscopic target located beyond the dashed circle (star #57, marked as a black-filled circle) is likely a Galactic field interloper and was excluded from the chemical analysis.