  The presence of Multiple Stellar Populations (MSPs) in Galactic Globular
Clusters (GCs) is a poorly understood phenomenon. By probing different spectral
ranges that are affected by different absorption lines using the multi-band
photometric survey S-PLUS, we study four GCs -- NGC 104, NGC 288, NGC 3201 and
NGC 7089 -- that span a wide range in metallicities. With the combination of
broad and narrow-band photometry in 12 different filters from 3485A (u) to
9114A (z), we identified MSPs along the rectified red-giant branch in
colour-magnitude diagrams (CMDs) and separated them using a K-means clustering
algorithm. Additionally, we take advantage of the large Field of View of the
S-PLUS detector to investigate radial trends in our sample. We report on six
colour combinations that can be used to successfully identify two stellar
populations in all studied clusters and show that they can be characterized as
Na-rich and Na-poor. For both NGC 288 and NGC 7089, their radial profiles show
a clear concentration of 2P. This directly supports the formation theories that
propose an enrichment of the intra-cluster medium and subsequent star formation
in the more dense central regions. However, in the case of NGC 3201, the trend
is reversed. The 1P is more centrally concentrated, in direct contradiction
with previous literature studies. NGC 104 shows a well-mixed population. We
also constructed radial profiles up to 1 half-light radius of the clusters with
HST data to highlight that radial differences are lost in the inner regions of
the GCs and that wide-field studies are essential when studying this.
