Can I drive a Low-Side MOSFET from a High-Side Driver?
Yes, you can use the LTC7004 for driving a low-side switch.

Turn to the diagram of the output stage in the LTC7004 datasheet (fig.1).  Connect the TS pin to GND.  (The source of the low side N-channel MOSFET is also connected to GND.)  Connect the BST to the gate driving voltage.  Add a capacitor from BST to GND.  Place the capacitor near the BST pin.

Interestingly, the LTC7004 has got an internal charge pump which can generate a +12V gate drive voltage from the Vcc.  If you want to create, the gate drive voltage with the internal charge pump, then don't connect BST to an external gate drive voltage.  Keep the capacitor between BST and GND.