  Understanding the formation of multiple populations in globular clusters
(GCs) represents a challenge for stellar population studies. Nevertheless, the
outermost GC regions, which may retain information of the initial configuration
of the multiple populations, are poorly studied. We use synthetic spectra that
account for the chemical compositions of first- and second-population (1P, 2P)
stars of 47 Tucanae to identify the spectral regions that are sensitive to its
multiple populations. Hence, we defined new photometric bands that are
efficient to disentangle 1P and 2P giant stars from Gaia XP spectra. To test
these new filters, we constructed the pseudo two-color diagrams dubbed
chromosome maps (ChMs) and identified for the first time, 1P and 2P stars in
the outermost cluster regions of 47 Tucanae and outside the tidal radius. We
constructed similar diagrams for NGC3201, NGC6121, NGC6752, and NGC6397, thus
exploring GCs with different metallicities. The ChMs allowed us to clearly
disentangle 1P and 2P stars in the external regions of all clusters, with the
exception of the metal-poor NGC6397. Our findings, together with literature
results from more-internal regions, show that the 2P stars of 47 Tucanae and
NGC 3201 are more-centrally concentrated than the 1P, whereas the multiple
populations of NGC 6121, and NGC 6752 share the same radial distributions.
These radial behaviors are consistent with the GC formation scenarios where 2P
stars originate in the central regions. Noticeably, results on NGC 3201 are in
tension with the conclusion from recent work that its 1P is more centrally
concentrated than the 2P and might form with more central concentration.
