one can work via DP to HDMI cable
The other will likely need a USB Graphics card.
You may also purchase a DP active splitter. The last time I priced these the ones that didnt just mirror the split were around $100.
edit - There is also the risk that you will run into the max allowed resolution your GPU can attain. The 'spliiter would present itself as a 3840x1080 display to the gpu added to whatever resolution your laptop screen already runs at.