AGND is a localized internal ground for logic signals. A 1-Ω resistor is recommended to be connected between GND and AGND to isolate the noise from board ground to AGND.
There are other two components are connected to this local ground: 0.1-µF capacitor between VREG to AGND and Roc_adj resistor between OC_ADJ and AGND.
Capacitor for VREG should be placed close to VREG and AGND pins and connected without vias.