Altium Schematic Pin Grouping
You will have to go into the schematic component library editor and move the pins (if you want to change the default grouping). Alternatively, if you only want to change it for one schematic, you can open the properties for the component (double-click on it) and uncheck "Lock Pins". This will allow you to move the pins around in the schematic, rather than the schematic library and all future parts created from it.