Symbols in the official library are made for the generic usecase. If you do use the part in a different usecase then you will need to make a project specific symbol.
In this case i suggest to make a symbol where your two power outputs (as well as the two inputs) are stacked. This is the way to tell KiCad (ERC) that two pins are directly connected.
See Electrical type of schematic symbol pins (KiCad 4 and KiCad 5) section Connecting Multiple (Power) Output Pins