They can be used both ways for both applications. It is how they are wired into their surrounding circuit that makes the difference. For example, in the schematic they are shown horizontally which gives the impression they are in series but if you redraw the schematic they coud look as though they were amplifiers.
Using that schematic, consider what happens at the collector of the transistors when the input voltage is zero and when it is +1V:
When zero, there is no voltage between the base and emitter so the transistor does not conduct, assuming nothing off the schematic is influencing it, the collector voltage would be -14.5V.
Now look at what happens if the input voltage goes above about +2.5V. The emitter is then at about 0.65V more positive than the base and the transistor conducts. That brings it's collector voltage down to Vce so instead of -14.5V it will be close to zero.
My conclusion, those transistors are inverting level shifters. To see why they are used that way would require the remainder of the schematic, in particular how the supplies to the CMOS gates are configured.
Brian.